Fix signals/group button on Scene dock

tools/editor/scene_tree_editor.cpp

@@ -260,13 +260,21 @@ void SceneTreeEditor::_cell_button_pressed(Object *p_item,int p_column,int p_id)
 
 	} else if (p_id==BUTTON_SIGNALS) {
 
-		item->select(0);
+		editor_selection->clear();
+		editor_selection->add_node(n);
+
+		set_selected(n);
+
 		NodeDock::singleton->get_parent()->call("set_current_tab",NodeDock::singleton->get_index());
 		NodeDock::singleton->show_connections();
 
 	} else if (p_id==BUTTON_GROUPS) {
 
-		item->select(0);
+		editor_selection->clear();
+		editor_selection->add_node(n);
+
+		set_selected(n);
+
 		NodeDock::singleton->get_parent()->call("set_current_tab",NodeDock::singleton->get_index());
 		NodeDock::singleton->show_groups();
 	}