Updated Windows install doc to refer to PyCrypto 2.1

PyCrypto 2.0.1 caused deprecation warnings on Python 2.6,
because it used sha and md5 modules, which were replaced
by hashlib in Python 2.5.

doc/scapy/installation.rst

@@ -411,7 +411,7 @@ Graphs (conversations)
 
 WEP decryption
 
- * `PyCrypto <http://www.dlitz.net/software/pycrypto/>`_: `pycrypto-2.0.1.win32-py2.5.zip <http://www.voidspace.org.uk/cgi-bin/voidspace/downman.py?file=pycrypto-2.0.1.win32-py2.5.zip>`_ `pycrypto-2.0.1.win32-py2.6.exe <http://www.voidspace.org.uk/downloads/pycrypto-2.0.1.win32-py2.6.exe>`_
+ * `PyCrypto <http://www.dlitz.net/software/pycrypto/>`_: `pycrypto-2.1.0.win32-py2.5.zip <http://www.voidspace.org.uk/downloads/pycrypto-2.1.0.win32-py2.5.zip>`_ `pycrypto-2.1.0.win32-py2.6.zip <http://www.voidspace.org.uk/downloads/pycrypto-2.1.0.win32-py2.6.zip>`_
 
 Fingerprinting