userportal,webadmin: clear token on error

- Added code to clear the token on the client and
  reacquire it when retrying the attempt that errored out. This
  is to support scenarios where the token might have changed
  without the client knowing.

Change-Id: I66c08d021788ebee561d39907f06de22cfe77b22
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1112404
Signed-off-by: Alexander Wels <awels@redhat.com>