[mediaqueries-5] Unbreak the spec build now that CSS2 also provides an @media definition to bikeshed.

Author: dbaron

mediaqueries-5/Overview.bs

@@ -22,6 +22,7 @@ Link Defaults: css-cascade-3 (at-rule) @import
 </pre>
 
 <pre class=link-defaults>
+spec:css-conditional-3; type:at-rule; text:@media
 spec:css-values-3; type:value; text:in
 </pre>