build: Don't build geo-replication rpms when on EL5

Also fixes a typo bug where geo-replication isn't
being disabled correctly

Backport of http://review.gluster.org/#/c/7210/

BUG: 1074045
Change-Id: I0f8f632c4ed1bdde179d6d7278e10e196549ca38
Signed-off-by: Justin Clift <justin@gluster.org>
Reviewed-on: http://review.gluster.org/7297
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>