Remove duplicate script-blocking style sheet requirement

Author: domfarolino

cssom-1/Overview.bs

@@ -1542,15 +1542,6 @@ must be run:
  </ol>
 </div>
 
-A style sheet referenced by an <a>xml-stylesheet processing instruction</a> using the rules in this section, in the context of
-the {{Document}} of an <a>XML parser</a> is said to be
-<a>a style sheet that is blocking scripts</a> if the <code>ProcessingInstruction</code>
-<a>node</a> was created by that {{Document}}'s parser, and the style sheet was
-enabled when the node was created by the parser, the last time the
-<a>event loop</a> reached step 1, the node was in that Document,
-and the user agent hasn't given up on loading that particular style sheet
-yet. A user agent may give up on such a style sheet at any time.
-
 ### Requirements on user agents Implementing the HTTP Link Header ### {#requirements-on-user-agents-implementing-the-http-link-header}
 
 <!-- XXX ref, one day -->