Only send event when data has changed

Author: StonesmileGit

B9PartSwitch/PartSwitch/PartModifiers/ModuleFuelTanksHandler.cs

@@ -40,8 +40,8 @@ private void ApplyNode(ConfigNode sourceNode) {
                 evtDetails.Set<string>("volName", "Tankage");
                 evtDetails.Set<double>("newTotalVolume", volume);
                 module.part.SendEvent("OnPartVolumeChanged", evtDetails, 0);
+                module.Events.Send("ModuleDataChanged", moduleDataChangedEventDetails);
             }
-            module.Events.Send("ModuleDataChanged", moduleDataChangedEventDetails);
         }
     }
-}
+}