Always treat file conflicts during install as errors.

     Change: dont-filter-install-file-conflicts
     Purpose: Always treat file conflicts during install as errors.
     Reason: Mandriva takes a more stricter approach on allowing
                     file conflicts with policies requiring such cases to
                     be explicitly dealt with on packaging side rather than
                     relying on best effort. Several different versions
                     of package with same name or file names are therefore
                     not allowed when doing install ('rpm -i') of packages.