Same method when redrawing as when theme changed

(cherry picked from commit c123a8c4f503dc40aa4a5b10c9e8224cd58ff112)

scene/gui/rich_text_label.cpp

@@ -801,11 +801,7 @@ void RichTextLabel::_notification(int p_what) {
 		} break;
 		case NOTIFICATION_THEME_CHANGED: {
 
-			if (is_inside_tree() && use_bbcode) {
-				parse_bbcode(bbcode);
-				//first_invalid_line=0; //invalidate ALL
-				//update();
-			}
+			update();
 
 		} break;
 		case NOTIFICATION_DRAW: {