Anchor link wrong 'class' attribute

[garry.yao]

Reproducing Procedures

1. Load any of the sample page;
2. Open 'Link' dialog, fill in the following fields with values:
   • URL : '​http://ckeditor.com';
   • Advanced Tab -> Name : 'anchor_name';
3. Click 'OK' to insert the link.
4. Open the dialog again on the inserted link;
5. Check the value of 'Advanced Tab -> Class Name';

• Expected Result: Empty value.
• Actual Result: 'cke_anchor'.

[garry.yao]

WFM in trunk now.