Do not hardcode php53 in the rhel6 .spec file

Change-Id: I434a967064418a7ee02aec23a35f6908b1ca5db7
Merge commit 'refs/changes/17/1317/1' of ssh://gerrit.tuleap.net:29418/tuleap into stable

* ssh://gerrit.tuleap.net:29418/tuleap:
  Do not hardcode php53 in the rhel6 .spec file

Change-Id: I96a9a3d868a63faf12c7728e9c42e57bf3e50703
This is Tuleap 6.6.99.3

Change-Id: I513460080dfe1c59d56a8fcfc424d2710b70c383