Ported from 1.5.x: 71cbffce2acfa5c84a0efa099a35b045f6425735

(Fixes RPCSEC_GSS group mapping.)

Signed-off-by: suhrud <supatank@in.ibm.com>
Signed-off-by: Matt Benjamin <matt@linuxbox.com>

Conflicts:
	src/IdMapper/idmapper.c
	src/include/idmapper.h