core: Add audit log when removing networks from iSCSI bond.

Adding an audit log to indicate the user that the removed networks
from the iSCSI bond, will only take affect, after the Hosts will be
moved to maintenance and activated again.

Change-Id: I087818bb48cc9243e76b2cb850e6262104537f3c
Bug-Url: https://bugzilla.redhat.com/1126428
Signed-off-by: Maor Lipchuk <mlipchuk@redhat.com>