Fix unable to deselect audio effects

(cherry picked from commit cf39cc985bf79bbbfc04b72e85dbbfe42f88c64d)

editor/editor_audio_buses.cpp

@@ -912,6 +912,7 @@ EditorAudioBus::EditorAudioBus(EditorAudioBuses *p_buses, bool p_is_master) {
 	vb->add_child(effects);
 	effects->connect("item_edited", callable_mp(this, &EditorAudioBus::_effect_edited));
 	effects->connect("cell_selected", callable_mp(this, &EditorAudioBus::_effect_selected));
+	effects->connect("focus_exited", callable_mp(effects, &Tree::deselect_all));
 	effects->set_edit_checkbox_cell_only_when_checkbox_is_pressed(true);
 	SET_DRAG_FORWARDING_GCD(effects, EditorAudioBus);
 	effects->connect("item_mouse_selected", callable_mp(this, &EditorAudioBus::_effect_rmb));