main window: Fix error on "add to a graphing window" if !filter labels

Right-clicking and trying to graph a signal from a DBC with "Label filters"
unset would result in an error "Cannot find ID 0xNNN in DBC files(). Not adding
graph".

Filter labels unset is the default state when adding a new DBC file.

mainwindow.cpp

@@ -588,7 +588,7 @@ void MainWindow::setupSendToLatestGraphWindow()
     GraphParams param;
     QString signalName = getSignalNameFromPosition(contextMenuPosition);
     param.ID = getMessageIDFromPosition(contextMenuPosition);
-    DBC_MESSAGE *msg = dbcHandler->findMessageForFilter(param.ID, nullptr);
+    DBC_MESSAGE *msg = dbcHandler->findMessage(param.ID);
     if(msg)
     {
         DBC_SIGNAL *sig = msg->sigHandler->findSignalByName(signalName);