v.build.html: fix map name

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@58976 15284696-431f-4ddb-bdfa-cd5b030d7da7

vector/v.build/v.build.html

@@ -52,7 +52,7 @@ indeces, not only topology. For linked OGR layers
 index is created.
 
 <div class="code"><pre>
-v.build map=urbanareas option=build
+v.build map=urbanarea option=build
 </pre></div>
 
 Note that the vector map <i>urbanarea</i> must be located in the
@@ -65,7 +65,7 @@ standard output. Such information can be printed also for vector maps
 from other mapsets.
 
 <div class="code"><pre>
-v.build map=urbanareas option=dump
+v.build map=urbanarea option=dump
 </pre></div>
 
 <h2>SEE ALSO</h2>