use exisitng convotag first instead of trying to send to directly

llarp/handlers/tun.cpp

@@ -1109,10 +1109,13 @@ namespace llarp
         }
         // try sending it on an existing convotag
         // this succeds for inbound convos, probably.
-        if (SendToOrQueue(to, pkt.ConstBuffer(), type))
+        if (auto maybe = GetBestConvoTagFor(to))
         {
-          MarkIPActive(dst);
-          return;
+          if (SendToOrQueue(*maybe, pkt.ConstBuffer(), type))
+          {
+            MarkIPActive(dst);
+            return;
+          }
         }
         // try establishing a path to this guy
         // will fail if it's an inbound convo