Fixes Facts string comparisons in CentOS 7

CentOS Project has adopted a new rule for versioning numbers. The major number
matches the RHEL major number, but the minor number is generated from the
release date. For example, CentOS 7.1407.

Change-Id: I16876d033bdb8ee47fa7b3c2d25c41e6f1c1c83e
Fixes: rhbz#1117035
Signed-off-by: Gael Chamoulaud <gchamoul@redhat.com>