Use a GenericAudioProcessorEditor in the standalone wrapper if no editor is provided

modules/juce_audio_plugin_client/Standalone/juce_StandaloneFilterWindow.h

@@ -730,7 +730,8 @@ private:
     public:
         MainContentComponent (StandaloneFilterWindow& filterWindow)
             : owner (filterWindow), notification (this),
-              editor (owner.getAudioProcessor()->createEditorIfNeeded())
+              editor (owner.getAudioProcessor()->hasEditor() ? owner.getAudioProcessor()->createEditorIfNeeded()
+                                                             : new GenericAudioProcessorEditor (*owner.getAudioProcessor()))
         {
             Value& inputMutedValue = owner.pluginHolder->getMuteInputValue();
 
@@ -770,7 +771,8 @@ private:
             if (shouldShowNotification)
                 notification.setBounds (r.removeFromTop (NotificationArea::height));
 
-            editor->setBounds (r);
+            if (editor != nullptr)
+                editor->setBounds (r);
         }
 
     private:
@@ -830,9 +832,10 @@ private:
            #if JUCE_IOS || JUCE_ANDROID
             resized();
            #else
-            setSize (editor->getWidth(),
-                     editor->getHeight()
-                     + (shouldShowNotification ? NotificationArea::height : 0));
+            if (editor != nullptr)
+                setSize (editor->getWidth(),
+                         editor->getHeight()
+                         + (shouldShowNotification ? NotificationArea::height : 0));
            #endif
         }