Clear SceneTreeDock's previous node selection when removing edited scene

Author: aaronfranke

editor/editor_node.cpp

@@ -4096,6 +4096,7 @@ bool EditorNode::is_addon_plugin_enabled(const String &p_addon) const {
 void EditorNode::_remove_edited_scene(bool p_change_tab) {
 	// When scene gets closed no node is edited anymore, so make sure the editors are notified before nodes are freed.
 	hide_unused_editors(SceneTreeDock::get_singleton());
+	SceneTreeDock::get_singleton()->clear_previous_node_selection();
 
 	int new_index = editor_data.get_edited_scene();
 	int old_index = new_index;