fix hop limit defaults for android

src/mesh/ReliableRouter.cpp

@@ -14,9 +14,10 @@ ErrorCode ReliableRouter::send(MeshPacket *p)
 {
     if (p->want_ack) {
         // If someone asks for acks on broadcast, we need the hop limit to be at least one, so that first node that receives our
-        // message will rebroadcast
+        // message will rebroadcast.  But asking for hop_limit 0 in that context means the client app has no preference on hop counts
+        // and we want this message to get through the whole mesh, so use the default.
         if (p->to == NODENUM_BROADCAST && p->hop_limit == 0)
-            p->hop_limit = 1;
+            p->hop_limit = HOP_RELIABLE;
 
         auto copy = packetPool.allocCopy(*p);
         startRetransmission(copy);