fix SSL problem

fix issue 173. originated by kvvier(https://code.google.com/u/kvvier/) and verified for python3.3 (win) by (https://code.google.com/u/111191101025126589579/), and me for python3.4 (linux)

As the modification of !disable_ssl_certificate_validation, I got following error when I try to install:
byte-compiling build/bdist.linux-armv7l/egg/httplib2/init.py to init.cpython-34.pyc
File "build/bdist.linux-armv7l/egg/httplib2/init.py", line 829
check_hostname=!disable_ssl_certificate_validation)
^
SyntaxError: invalid syntax

So I suggest the change kvvier