aaa: Failure to add user name in rest-api due to wrong username

Change-Id: Ic3354f48ebd1027e2d15675b27811931dcbdbe1e
Topic: AAA
Bug-Url: https://bugzilla.redhat.com/1138253
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>