fixed link to graph library in change comment

[SVN r9944]

index.htm

@@ -57,7 +57,7 @@ with any concerns you don't want to just post to the mailing list.</p>
     added:&nbsp; Help for non-conforming standard libraries from Ralf Grosse-Kunstleve.</li>
   <li><a href="libs/random/index.html">Random Number Library</a>: Split into separate headers, updated documentation, added lagged_fibonacci generator.</li>
   <li><a href="libs/integer/index.htm">Integer Library</a>: Minor portability update.</li>
-  <li><a href="libs/graph/index.html">Graph Library</a>: Changed algorithm interfaces to use named parameters technique. Added graph isomorphism algorithm.</li>
+  <li><a href="libs/graph/doc/table_of_contents.html">Graph Library</a>: Changed algorithm interfaces to use named parameters technique. Added graph isomorphism algorithm.</li>
 </ul>
 <p>March 14, 2001 - Version 1.21.1</p>
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