Position may be null

Fixes #51662

src/vs/editor/contrib/codeAction/lightBulbWidget.ts

@@ -53,7 +53,7 @@ export class LightBulbWidget implements IDisposable, IContentWidget {
 			const { lineHeight } = this._editor.getConfiguration();
 
 			let pad = Math.floor(lineHeight / 3);
-			if (this._position.position.lineNumber < this._model.position.lineNumber) {
+			if (this._position && this._position.position.lineNumber < this._model.position.lineNumber) {
 				pad += lineHeight;
 			}