userportal: No null to display

- Fixed missing entity title for UserPortalListModel.

Change-Id: I4bea19ac57ede41a8da8e3c3611028f9d15ec2a7
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=894306
Signed-off-by: Alexander Wels <awels@redhat.com>