webadmin: Fixed UI for popup New CPU QoS

In the popup "New CPU Qos", the scroll bar was removed and also,
margin was added for the "Limit" textbox so it will be aligned with the
rest of the textboxes.

Color for the "Limit" row wasn't changed(It was decided to leave it
as is).

Change-Id: I4aebf602a70b7b65f65d45e388b5d49296ed0be7
Bug-Url: https://bugzilla.redhat.com/1142813
Signed-off-by: Tomer Saban <tsaban@redhat.com>