lavinmq holds mesh-broker again, now the check reads the store

The claim comes back for the third and last time. The store's row says the bus seat
answers for `amqp`, lavinmq provides `amqp`, and with mesh-controller#89 the check
that judges a claim reads that row instead of a copy compiled into the build
machine. So this is accepted for the reason it should have been all along.

Restores the holder the controller composes its own bus address through, which is
what ends tonight's crash loop. nats takes the seat over when the cutover is done
deliberately, not because the seat emptied itself.

modules/lavinmq/module.json

@@ -7,6 +7,12 @@
       "scope": "mesh"
     }
   ],
+  "claims": [
+    {
+      "name": "mesh-broker",
+      "scope": "mesh"
+    }
+  ],
   "capabilities": [
     "container-runtime"
   ],