Update connect.py

Fixing a bug on windows 7 32 bit : 

[IPythonQtConsoleApp] ERROR | Could not setup tunnels
Traceback (most recent call last):
  File "C:\Anaconda\lib\site-packages\IPython\consoleapp.py", line 304, in init_
ssh
    newports = tunnel_to_kernel(info, self.sshserver, self.sshkey)
  File "C:\Anaconda\lib\site-packages\IPython\kernel\connect.py", line 364, in t
unnel_to_kernel
    password = getpass("SSH Password for %s: "%sshserver)
  File "C:\Anaconda\lib\getpass.py", line 95, in win_getpass
    msvcrt.putch(c)
TypeError: must be char, not unicode
[IPythonQtConsoleApp] Exiting application: ipython-qtconsole
When calling getpass,
TypeError: must be char, not unicode
Use cast_bytes_py2 for getpass() prompt
Merge pull request #4346 from takluyver/win-kernel-getpass

getpass() on Windows & Python 2 needs bytes prompt