docs(guide/forms): fix url-based links refs to AUTO module

Request Type: docs

How to reproduce: 

Component(s): 

Impact: small

Complexity: small

This issue is related to: 

**Detailed Description:**

The links do not work. 

I think at commit https://github.com/angular/angular.js/commit/a564160511bf1bbed5a4fe5d2981fae1bb664eca, this correction has been forgotten.

**Other Comments:**