Clean up plugins using settings.

packages/codemirror-extension/src/index.ts

@@ -99,8 +99,8 @@ function activateEditorCommands(app: JupyterLab, tracker: IEditorTracker, mainMe
    * Update the setting values.
    */
   function updateSettings(settings: ISettingRegistry.ISettings): void {
-    const matched = settings.get('matchBrackets') as boolean | null;
-    matchBrackets = matched === null ? matchBrackets : matched as boolean;
+    const cached = settings.get('matchBrackets') as boolean | null;
+    matchBrackets = cached === null ? false : !!cached;
     keyMap = settings.get('keyMap') as string | null || keyMap;
     theme = settings.get('theme') as string | null || theme;
   }

packages/fileeditor-extension/src/index.ts

@@ -110,10 +110,9 @@ function activate(app: JupyterLab, registry: IDocumentRegistry, restorer: ILayou
    */
   function updateSettings(settings: ISettingRegistry.ISettings): void {
     let cached = settings.get('lineNumbers') as boolean | null;
-    lineNumbers = cached === null ? lineNumbers : !!cached;
-
+    lineNumbers = cached === null ? false : !!cached;
     cached = settings.get('wordWrap') as boolean | null;
-    wordWrap = cached === null ? wordWrap : !!cached;
+    wordWrap = cached === null ? false : !!cached;
   }
 
   /**