webadmin: Change height of label widgets

Played around with the heights to make dialogs related to the label
widgets look tighter.

Change-Id: Iff2e5474b4d407380f713a9f1312e778cfb9c446
Bug-Url: https://bugzilla.redhat.com/1030955
Signed-off-by: Lior Vernia <lvernia@redhat.com>