do not guess python versions in dh_python2
do not guess python versions in dh_python2

This was a fix necessary on Debian wheezy.

benthomasson/stdeb,pombredanne/stdeb,astraw/stdeb,LeMeteore/stdeb,benthomasson/stdeb,astraw/stdeb,sathieu/stdeb,pombredanne/stdeb,astraw/stdeb,benthomasson/stdeb,sathieu/stdeb,LeMeteore/stdeb,sathieu/stdeb,pombredanne/stdeb,LeMeteore/stdeb