stop propagating when we are done with a stanza

src/plugins/ping.rs

@@ -51,7 +51,7 @@ impl PingPlugin {
                 });
             }
         }
-        Propagation::Continue
+        Propagation::Stop
     }
 
     fn reply_ping(&self, ping: &PingEvent) -> Propagation {

src/plugins/stanza.rs

@@ -40,7 +40,7 @@ impl StanzaPlugin {
             self.proxy.dispatch(iq);
         }
 
-        Propagation::Continue
+        Propagation::Stop
     }
 }