Fix reinplace in macports package to work on both 10.7 and 10.8

This is a macports packaging fix, I had to install ansible on a few of my colleagues laptops today to reproduce a development/test/integration environment and came across some differences in macports/osx between 10.7 and 10.8.

reinplace on OSX 10.8 seems to behave differently, this change has been tested
on a few 10.8 and 10.7 machines.

It seems to work for me, but please test!