Port from PyCrypto to PyCroptodome

As the PyCrypto website says [1]:

> PyCrypto 2.x is unmaintained, obsolete, and contains security
> vulnerabilities.

Therefore, switch to PyCryptodome, a maintained PyCrypto fork
which is listed there as the recommended alternative for
existing software that depends on PyCrypto.

Notes on the port:

1) As the PyCryptodome introduction documentation [2] says,
there are 2 alternative projects/namespaces that can be
used:

* pycryptodome, which uses the `Crypto` package
  that PyCrypto also uses, so is almost a drop-in
  replacement for Pycrypto

* pycryptodomex, which uses the `Cryptodome` package

It also mentions that the use of pycryptodome
"is therefore recommended only when you are
sure that the whole application is deployed in a virtualenv".

Since it isn't sure that the application is deployed in a
virtualenv, to make it more explicit that PyCryptodome
is being used and because Linux distros like Debian
package the `Cryptodome` package [3], the port is done to
the `pycryptodomex` library that uses the `Cryptodome`
package name.

2) As the "Compatibility with PyCrypto" page in the PyCryptodome
doc [4] says:

> The following packages, modules and functions have been removed:
>
> * Crypto.Random.OSRNG, Crypto.Util.winrandom and Crypto.Random.randpool.
>   You should use Crypto.Random only.

The `PublicKey.RSA.generate` method already uses
`Crypto.Random.get_random_bytes()` as default [5],
so just drop the second parameter using `RandomPool.getBytes`
in `virtualsmartcard/src/vpicc/virtualsmartcard/cards/cryptoflex.py`.

[1] https://www.pycrypto.org/
[2] https://www.pycryptodome.org/src/introduction
[3] https://packages.debian.org/bullseye/python3-pycryptodome
[4] https://pycryptodome.readthedocs.io/en/latest/src/vs_pycrypto.html
[5] https://pycryptodome.readthedocs.io/en/latest/src/public_key/rsa.html

docs/virtualsmartcard/README.html

@@ -211,7 +211,7 @@ responses via NFC to a contact-less smart card that signs the mail.</p>
 <ul class="simple">
 <li><p><a class="reference external" href="http://www.python.org/">Python</a> <a class="footnote-reference brackets" href="#id7" id="id8">3</a></p></li>
 <li><p><a class="reference external" href="http://pyscard.sourceforge.net/">pyscard</a> <a class="footnote-reference brackets" href="#id9" id="id10">4</a> (relaying a local smart card with <cite>–type=relay</cite>)</p></li>
-<li><p><a class="reference external" href="http://pycrypto.org/">PyCrypto</a> <a class="footnote-reference brackets" href="#id11" id="id12">5</a>, <a class="reference external" href="https://www.dlitz.net/software/python-pbkdf2/">PBKDF2</a> <a class="footnote-reference brackets" href="#id13" id="id14">6</a>, <a class="reference external" href="http://www.pythonware.com/products/pil/">PIL</a> <a class="footnote-reference brackets" href="#id19" id="id20">9</a>, <a class="reference external" href="https://docs.python.org/3.3/library/readline.html">readline</a> <a class="footnote-reference brackets" href="#id15" id="id16">7</a> or <a class="reference external" href="https://pypi.python.org/pypi/pyreadline">PyReadline</a> <a class="footnote-reference brackets" href="#id17" id="id18">8</a> (emulation of electronic
+<li><p><a class="reference external" href="https://www.pycryptodome.org/">PyCryptodome</a> <a class="footnote-reference brackets" href="#id11" id="id12">5</a>, <a class="reference external" href="https://www.dlitz.net/software/python-pbkdf2/">PBKDF2</a> <a class="footnote-reference brackets" href="#id13" id="id14">6</a>, <a class="reference external" href="http://www.pythonware.com/products/pil/">PIL</a> <a class="footnote-reference brackets" href="#id19" id="id20">9</a>, <a class="reference external" href="https://docs.python.org/3.3/library/readline.html">readline</a> <a class="footnote-reference brackets" href="#id15" id="id16">7</a> or <a class="reference external" href="https://pypi.python.org/pypi/pyreadline">PyReadline</a> <a class="footnote-reference brackets" href="#id17" id="id18">8</a> (emulation of electronic
 passport with <cite>–type=ePass</cite>)</p></li>
 <li><p><a class="reference external" href="https://github.com/frankmorgner/openpace">OpenPACE</a> <a class="footnote-reference brackets" href="#id21" id="id22">10</a> (emulation of German identity card with <cite>–type=nPA</cite>)</p></li>
 <li><p><a class="reference external" href="https://fukuchi.org/works/qrencode/">libqrencode</a> <a class="footnote-reference brackets" href="#id23" id="id24">11</a> (to print a QR code on the command line for <cite>vpcd-config</cite>; an
@@ -563,7 +563,7 @@ more than welcome! Please use our <a class="reference external" href="https://gi
 <dd><p><a class="reference external" href="http://pyscard.sourceforge.net/">http://pyscard.sourceforge.net/</a></p>
 </dd>
 <dt class="label" id="id11"><span class="brackets"><a class="fn-backref" href="#id12">5</a></span></dt>
-<dd><p><a class="reference external" href="http://pycrypto.org/">http://pycrypto.org/</a></p>
+<dd><p><a class="reference external" href="https://www.pycryptodome.org/">https://www.pycryptodome.org/</a></p>
 </dd>
 <dt class="label" id="id13"><span class="brackets"><a class="fn-backref" href="#id14">6</a></span></dt>
 <dd><p><a class="reference external" href="https://www.dlitz.net/software/python-pbkdf2/">https://www.dlitz.net/software/python-pbkdf2/</a></p>
@@ -619,4 +619,4 @@ more than welcome! Please use our <a class="reference external" href="https://gi
   </div>
 </footer>
   </body>
-</html>
+</html>