Remove prefix from chat messages

As the wormhole user only ever posts messages from the other side of the
wormhole, we don't need to see the protocol name before every single
message.

scripts/xmpp-muc-bridge.js

@@ -11,7 +11,7 @@ module.exports = function (robot) {
     if (!xmppRooms.includes(conference)) return;
 
     const room = hubotRooms[xmppRooms.indexOf(conference)];
-    const msg = `[xmpp] <${from}> ${message}`;
+    const msg = `<${from}> ${message}`;
 
     robot.messageRoom(room, msg);
   });
@@ -34,7 +34,7 @@ module.exports = function (robot) {
       if (!hubotRooms.includes(message.user.room)) return;
 
       const room = xmppRooms[hubotRooms.indexOf(message.user.room)];
-      const msg = `[irc] <${message.user['id']}> ${message.text}`;
+      const msg = `<${message.user['id']}> ${message.text}`;
 
       xmpp.send(room, msg, true);
     }