core: Unable to search on domain for users with some search options.

Search failed, when try to search user on domain
with special keyword.

This happens when user search by lastname, department
and title.

Fix for IPA, OpenLDAP and RHDS

Change-Id: I351a8c0e3341a6f975efec210398267aa828c3e0
Bug-Url: https://bugzilla.redhat.com/975380
Signed-off-by: Ravi Nori <rnori@redhat.com>