Revert "Relax a bit the permissions on /var/lib/gitolite{/,/repositories}."

This doesn't work, applying this ends in a Puppet error: "Only
subclasses can override parameters". It seems that for that kind of
trick to work, we'd have to use resource collector, or use a subclass
that would inherit from the main gitolite class.

This reverts commit 91c354cb.