Python2 package is libre now - manual intervention required

Python upstream made a release of their 2.7 branch after and were relicensed which made this modules free as in freedom. This means Parabola's python2-libre isn't needed anymore since version 2.7.3 and it will be removed from repos.

You should install the python2 package manually using regular pacman methods. Accept the python2-libre removal and that's it :)