webadmin: Unite broken lines in AppErrors.properties

The entry for LABELED_NETWORK_ATTACHED_TO_WRONG_INTERFACE
is split into two lines.

Change-Id: I5d140e1dbe20e7945bc04b85cd9010441c643f6f
Bug-Url: https://bugzilla.redhat.com/1065713
Signed-off-by: Moti Asayag <masayag@redhat.com>