Bug 1140676 - Exception logged while inventorying EAP 6 host controller after setting http-interface

Throw IPCE when security realm is not ready so that a proper resource
error shows up in the GUI.

(cherry picked from commit 9c1d53de54065ac9240df9c5d526fef04b09419c)
Signed-off-by: Libor Zoubek <lzoubek@redhat.com>