Remove unnecessary line break

Co-authored-by: Athan <kgryte@gmail.com>

packages/toc/src/extension.ts

@@ -13,7 +13,6 @@ import { IMarkdownViewerTracker } from '@jupyterlab/markdownviewer';
 import { INotebookTracker } from '@jupyterlab/notebook';
 import { IRenderMimeRegistry } from '@jupyterlab/rendermime';
 import { ISettingRegistry } from '@jupyterlab/settingregistry';
-
 import { TableOfContents } from './toc';
 import {
   createLatexGenerator,