Test Results:

[root@ask-02 ~]# ccs -f testcluster2.conf --createcluster testcluster
[root@ask-02 ~]# ccs -f testcluster2.conf --setuidgid uid=testuid gid=testgid
[root@ask-02 ~]# cat testcluster2.conf | grep uidgid
  <uidgid gid="testgid" uid="testuid"/>
[root@ask-02 ~]# ccs -f testcluster2.conf --rmuidgid uid=testuid gid=testgid
Removing uid=testuid, gid=testgid
[root@ask-02 ~]# cat testcluster2.conf | grep uidgid
[root@ask-02 ~]# rpm -q ccs
ccs-0.16.2-69.el6_5.1.x86_64

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

http://rhn.redhat.com/errata/RHBA-2013-1821.html