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.

Change-Id: I8836893dfcdf457d9c5d766612d687bfce64e2ae
BUG: 1126802
Signed-off-by: Lalatendu Mohanty <lmohanty@redhat.com>
Reviewed-on: http://review.gluster.org/8994
Reviewed-by: Niels de Vos <ndevos@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>