spec: start/enable glusterd

This patch will enable/disable glusterd service after install/remove
of ovirt-node-plugin-vdsm

Change-Id: Ica02b068914a8ae9aaf8c452175db969badc4e6e
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1073531
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>