fix pygrass manual link

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@60582 15284696-431f-4ddb-bdfa-cd5b030d7da7

man/build_html.py

@@ -166,7 +166,7 @@ r"""<!-- the files grass7.html & helptext.html file live in lib/init/ -->
       </td>
       <td valign="top" bgcolor="${box_color}" class="box"><h3>&nbsp;Python</h3>
        <ul>
-        <li class="box"><a href="pygrass">PyGRASS documentation</a></li>
+        <li class="box"><a href="pygrass/index.html">PyGRASS documentation</a></li>
        </ul>
       </td>
     </tr>