v.external: manual cosmetics (author -> authors)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@60967 15284696-431f-4ddb-bdfa-cd5b030d7da7

vector/v.external/v.external.html

@@ -99,7 +99,7 @@ maintaining attributes in external DBMS in also writable mode.
 See
 also GRASS <a href="http://grasswiki.osgeo.org/wiki/Working_with_external_data_in_GRASS_7">user wiki page</a> for more examples.
 
-<h2>AUTHOR</h2>
+<h2>AUTHORS</h2>
 
 Radim Blazek, ITC-Irst, Trento, Italy
 <br>