Remove note about deleting callback tokens, It's done for all stale callbacks.

protocol/sacn/arbitratinguniverse.cpp

@@ -119,9 +119,6 @@ void ArbitratingUniverse::deleteSourceUniverse(const DATA::data_header& src)
 {
   if (!hasSourceUniverse(src))
     return;
-
-  /// \todo also erase token for data change callbacks
-
   sources_.erase(src);
   doListChangeCallbacks();
 }
@@ -171,9 +168,8 @@ void ArbitratingUniverse::doListChangeCallbacks()
       ++it;
     }
     else
-    { // or remove the callback
+      // or remove the callback
       it = cb_sourceListChange.erase(it);
-    }
   }
 }