Fix syntax error

[bochecha]

No description provided.

[bochecha]

A bit more context here.

The problem only happens with Python 3, not Python 2:

$ python2
Python 2.7.5 (default, Jun 25 2014, 10:19:55) 
[GCC 4.8.2 20131212 (Red Hat 4.8.2-7)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> def foo(s):
...     if isinstance(s, str):
...         print(s)
...         return
...     raise TypeError, 'unexpected type "%s"' % repr(s)
... 
>>> 

$ python3
Python 3.3.2 (default, Jun 30 2014, 17:20:03) 
[GCC 4.8.3 20140624 (Red Hat 4.8.3-1)] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> def foo(s):
...     if isinstance(s, str):
...         print(s)
...         return
...     raise TypeError, 'unexpected type "%s"' % repr(s)
  File "<stdin>", line 5
    raise TypeError, 'unexpected type "%s"' % repr(s)
                   ^
SyntaxError: invalid syntax
>>> 

The problem is in a file that is completely unused in Python 3 (py2.py).

However, that file still gets installed when building for Python 3.

So, when building the Fedora package python3-pygit2, the file is installed, and we then use Python 3 to byte-compile it, which causes the build to fail due to the SyntaxError.

This pull request fixes the problem by simply using a syntax which works both in Python 2 and 3.

Another way to fix it is to make sure the file isn't installed when building for Python 3 (and of course that py3.py doesn't get installed when building for Python 2)

However, I prefered going with the simpler solution first. 😃