volume set nfs.rpc-auth-allow and nfs.rpc-auth-reject succeeds, and the vol info gets updated, but the nfs server volfile is not updated.
PATCH: http://patches.gluster.com/patch/7102 in master (set: Fix incorrect nfs.rpc-auth strings in nfs_option_handler)
PATCH: http://patches.gluster.com/patch/7104 in release-3.1 (set: Fix incorrect nfs.rpc-auth strings in nfs_option_handler)
verified on release-3.3.0qa11