r.statistics: r.category link fixed in manual page (merged from devbr6, https://trac.osgeo.org/grass/changeset/31500)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@31501 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.statistics/description.html

@@ -89,7 +89,7 @@ r.univar fieldelev
 <a href="r.mapcalc.html">r.mapcalc</a>,
 <a href="r.neighbors.html">r.neighbors</a>,
 <a href="r.univar.html">r.univar</a>
-<a href="r.category">r.category</a>
+<a href="r.category.html">r.category</a>
 </em>
 
 <h2>AUTHOR</h2>