webadmin: Added scrolling to vNIC profiles

In add/edit network, added a vertical scroll bar to the vNIC profile
section.

Change-Id: I2fedc75dfcd534775fdb80b3364b81d99aab74eb
Bug-Url: https://bugzilla.redhat.com/1012798
Signed-off-by: Lior Vernia <lvernia@redhat.com>