r.relief: note in manual that current mask is ignored

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@73612 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.relief/r.relief.html

@@ -46,6 +46,9 @@ use <em><a href="r.resamp.interp.html">r.resamp.interp</a></em> with
 bilinear or bicubic method to resample the DEM at higher
 resolution. <em>r.relief</em> is then run on the resampled DEM.
 
+<p>
+The current mask is ignored.
+
 <h2>EXAMPLES</h2>
 
 <h3>Shaded relief map</h3>