logrotate: gluster logrotate config should not be global

Issue : Previously glusterfs logrotate config file pollutes
global config. So moved the directives inside the curly braces,
so they don't pollute the global config state.

Backport of fix from BZ 1126801, http://review.gluster.org/#/c/9001/

Change-Id: Iafaa6bb295b7dd7554c2654716cc9aeafd6d7a68
BUG: 1158923
Signed-off-by: Kaleb S. KEITHLEY <kkeithle@redhat.com>
Reviewed-on: http://review.gluster.org/9013
Reviewed-by: Humble Devassy Chirammal <humble.devassy@gmail.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Lalatendu Mohanty <lmohanty@redhat.com>
Reviewed-by: Justin Clift <justin@gluster.org>