userportal,webadmin: IE9 header value

- Fixed issue where IE9 was reporting missing headers as
  blank instead of null. This would cause initialization
  routined to be executed, and that would cause another
  request which would cause the header to be missing again
  and one would end up in an endless loop of requests. The
  patch checks for both null and blank so the loop never
  happens.

Change-Id: I4144a585a1dec1e736d30f7b7b698687543f7936
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1114863
Signed-off-by: Alexander Wels <awels@redhat.com>