vdsm.spec: glusterfs 3.4

Glusterfs 3.4 package now available at Koji, updating the spec.

Change-Id: I16bf2f5bbc606b55440cf04e7d5e08bcdc7729a5
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/16894
Reviewed-by: Dan Kenigsberg <danken@redhat.com>