chore(tests): fix warning about a non-unique element locator in e2e tests

src/ng/sce.js

@@ -623,7 +623,7 @@ function $SceDelegateProvider() {
  * <file name="protractor.js" type="protractor">
  *   describe('SCE doc demo', function() {
  *     it('should sanitize untrusted values', function() {
- *       expect(element(by.css('.htmlComment')).getInnerHtml())
+ *       expect(element.all(by.css('.htmlComment')).first().getInnerHtml())
  *           .toBe('<span>Is <i>anyone</i> reading this?</span>');
  *     });
  *