Fixed unraised exception in _disallow_write for LDAP
Fixed unraised exception in _disallow_write for LDAP

Issue introduced by commit [0]

0. I13eada3d5c3a166223c3e3ce70b7054eaed1003a

Change-Id: I225daf0e00742c54d5d009e456d4a3ad864356a0

openstack/keystone,mahak/keystone,openstack/keystone,mahak/keystone,openstack/keystone,ilay09/keystone,mahak/keystone,rajalokan/keystone,rajalokan/keystone,rajalokan/keystone,ilay09/keystone,ilay09/keystone