engine: Typo in welcome page.

- Fixed typo in welcome page, changed Administrator
  portal, to Administration portal.

Change-Id: I6a45d39de3f7268b653d388dab4357839a30ea4c
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1011437
Signed-off-by: Alexander Wels <awels@redhat.com>