trap-manager: Remove reqid parameter from install() and change return type

Reqids for the same traffic selectors are now stable so we don't have to
pass reqids of previously installed CHILD_SAs.  Likewise, we don't need
to know the reqid of the newly installed trap policy as we now uninstall
by name.

src/libcharon/sa/ikev2/tasks/child_delete.c

@@ -374,8 +374,8 @@ static status_t destroy_and_reestablish(private_child_delete_t *this)
 					break;
 				case ACTION_ROUTE:
 					charon->traps->install(charon->traps,
-							this->ike_sa->get_peer_cfg(this->ike_sa), child_cfg,
-							reqid);
+									this->ike_sa->get_peer_cfg(this->ike_sa),
+									child_cfg);
 					break;
 				default:
 					break;