rpm: package /var/run/gluster so that statedumps can be created

Creating statedumps fail when /var/run/gluster does not exist. This
directory should be part of the 'glusterfs' package that is installed on
storage servers and native clients.

BUG: 917561
Change-Id: Ibbc1e4016469fab3db0423337fabc4ba5a8302ab
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: http://review.gluster.org/4616
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Kaleb KEITHLEY <kkeithle@redhat.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>