revert unintended changes

Author: dnfield

shell/common/engine.cc

@@ -309,6 +309,8 @@ void Engine::DispatchPlatformMessage(std::unique_ptr<PlatformMessage> message) {
       runtime_controller_->DispatchPlatformMessage(std::move(message))) {
     return;
   }
+
+  FML_DLOG(WARNING) << "Dropping platform message on channel: " << channel;
 }
 
 bool Engine::HandleLifecyclePlatformMessage(PlatformMessage* message) {