Avoid deleting ports assigned to router interfaces

Even though this method is marked to be removed, in
the meantime the fact that it's being agressive in
deleting all ports might mask underlying failures
with the remove_interface API call, so it's best to
relax it now to help catch potential gate failures.

Change-Id: I835942fb59ef8244f39fab59073e68c5bee3e44a
Close-bug: 1253848
1 file changed