webadmin: increase guide me button size

- Increase the size of the guide me buttons
  to be the width of the popup window so it
  doesn't cut of messages in other locales.

Change-Id: I686165f9b93b36ad664ddaee50df268b76a2347e
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1121108
Signed-off-by: Alexander Wels <awels@redhat.com>