Remove outdated _.runInContext example. [ci skip]

lodash.js

@@ -1404,13 +1404,6 @@
    * lodash.isFunction(lodash.bar);
    * // => true
    *
-   * // Use `context` to stub `Date#getTime` use in `_.now`.
-   * var stubbed = _.runInContext({
-   *   'Date': function() {
-   *     return { 'getTime': stubGetTime };
-   *   }
-   * });
-   *
    * // Create a suped-up `defer` in Node.js.
    * var defer = _.runInContext({ 'setTimeout': setImmediate }).defer;
    */