docs(ngModel.NgModelController): Remove extra 'to'

src/ng/directive/input.js

@@ -1625,7 +1625,7 @@ var VALID_CLASS = 'ng-valid',
  *
  * We are using the {@link ng.service:$sce $sce} service here and include the {@link ngSanitize $sanitize}
  * module to automatically remove "bad" content like inline event listener (e.g. `<span onclick="...">`).
- * However, as we are using `$sce` the model can still decide to to provide unsafe content if it marks
+ * However, as we are using `$sce` the model can still decide to provide unsafe content if it marks
  * that content using the `$sce` service.
  *
  * <example name="NgModelController" module="customControl" deps="angular-sanitize.js">