pluto: Added support for statically configured reqids.

src/pluto/connections.c

@@ -1191,7 +1191,7 @@ void add_connection(const whack_message_t *wm)
 		}
 
 		c->spd.next = NULL;
-		c->spd.reqid = gen_reqid();
+		c->spd.reqid = wm->reqid ?: gen_reqid();
 
 		c->spd.mark_in.value = wm->mark_in.value;
 		c->spd.mark_in.mask = wm->mark_in.mask;