fix(input): don't perform HTML5 validation on updated model-value

Running html5-validation immediately after model-value is updated is incorrect, because the view
has not updated, and HTML5 constraint validation has not adjusted.

Closes angular#6796

src/ng/directive/input.js

@@ -874,7 +874,6 @@ function addNativeHtml5Validators(ctrl, validatorName, element) {
       return value;
     };
     ctrl.$parsers.push(validator);
-    ctrl.$formatters.push(validator);
   }
 }