r.covar manual: fix m.eigensystem reference (still points to G6 Addons)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@60043 15284696-431f-4ddb-bdfa-cd5b030d7da7

raster/r.covar/r.covar.html

@@ -8,7 +8,6 @@ output into a file.
 The output is an N x N symmetric covariance (correlation) matrix, 
 where N is the number of raster map layers specified on the command line. 
 
-
 <h2>NOTES</h2>
 
 This module can be used as the first step of a principle components 
@@ -18,9 +17,9 @@ eigen values and eigen vectors. An NxN covariance matrix would result in
 N real eigen values and N eigen vectors (each composed of N real numbers). 
 
 <p>
-The module <em><a href="m.eigensystem.html">m.eigensystem</a></em> in
-src.contrib can be compiled and used to generate the eigen values and
-vectors.
+The module <em><a href="http://grasswiki.osgeo.org/wiki/AddOns/GRASS_6#m.eigensystem">m.eigensystem</a></em>
+in <a href="http://grass.osgeo.org/download/addons/">GRASS GIS Addons</a>
+can be compiled and used to generate the eigen values and vectors.
 
 <h2>EXAMPLE</h2>