webadmin: Clearing float from AddRemoveRowPanel

Adding <div style="clear: both;"/> after AddRemoveRowPanel to make sure
next AddRemoveRowPanel will be in a new line.

Change-Id: I508d61b3f9b65334306c40b2581e7b20fafcff75
Bug-Url: https://bugzilla.redhat.com/1064749
Signed-off-by: Mike Kolesnik <mkolesni@redhat.com>