Fix link to bcp in the tools page.

[SVN r61239]

tools/index.html

@@ -71,7 +71,7 @@
                Extensible Stylesheet Language (XSL)</a>, used by some Boost libraries.<br>
          &nbsp;
          <li>
-            <a href="bcp/bcp.html">bcp</a> - A utility to extract subsets of Boost; to 
+            <a href="bcp/index.html">bcp</a> - A utility to extract subsets of Boost; to 
             determine which parts of Boost your code is using; and to print reports on 
             Boost usage (including Licence information).<br>
          &nbsp;