working fix to build pymc with numpy-1.7 on a win32 environment

It is maybe not the smartest way, but it helps building the module for anaconda 1.7 on win-32.

I followed @twiecki suggestion and made that PR  (https://groups.google.com/a/continuum.io/forum/#!msg/anaconda/E3lUTyavS7Y/2bTwdIhHdk8J)

related issues:
 - ContinuumIO/anaconda-issues#7
 - ContinuumIO/conda-recipes/pull/16