mgmt/glusterd: error out if remove-brick comes for final bricks
mgmt/glusterd: error out if remove-brick comes for final bricks

Signed-off-by: Pranith Kumar K <pranithk@gluster.com>
Signed-off-by: Anand V. Avati <avati@dev.gluster.com>

BUG: 2298 (removing the last pair of bricks from a volume results in inconsistency)
URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2298

Kaushikbv/Gluster,Kaushikbv/Gluster,Kaushikbv/Gluster