webadmin: fixed vNIC widget in add/edit VM dialog

PatternFly patch caused vNIC widget in add/edit VM dialog to
have a misaligned label. Fixed.

Change-Id: Ib8edda05b9770dc4cbfc493a2f62f8c3124a33a6
Bug-Url: https://bugzilla.redhat.com/1096845
Signed-off-by: Greg Sheremeta <gshereme@redhat.com>