userportal,webadmin: user domain selection

- Fixed issue if there are more than one domains and you
  selected one that wasn't the default, the domain value
  would not be propagated by the GWT editor to the model.

Change-Id: I396ca930862354b0c0c0c5e5341a0680521ece2e
Signed-off-by: Alexander Wels <awels@redhat.com>