[css-navigation-1] Remove obsolete bikeshed workaround and comment describing it.

Author: dbaron

css-navigation-1/Overview.bs

@@ -3,7 +3,6 @@ Title: CSS Route Matching
 Status: ED
 Work Status: Exploring
 Shortname: css-navigation
-Org: w3c
 Level: 1
 Group: csswg
 ED: https://drafts.csswg.org/css-navigation-1/
@@ -13,7 +12,6 @@ Editor: Noam Rosenthal, Google https://www.google.com/, w3cid 121539
 Abstract: This module contains conditional CSS rules for styling conditioned on the current URL
         or conditioned on the status of navigating between particular URLs.
 </pre>
-<!-- for now using Org: w3c rather than Group: csswg because the latter forces an incorrect issue tracking link, overriding Repository -->
 
 <pre class="link-defaults">
 spec:css-values-5; type:function; text:if()