g.region: Read vector header only for performance improvement

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@61075 15284696-431f-4ddb-bdfa-cd5b030d7da7

general/g.region/main.c

@@ -510,7 +510,7 @@ int main(int argc, char *argv[])
 	    temp_window = window;
 
 	    Vect_set_open_level(2);
-	    if (2 > Vect_open_old(&Map, vect_name, mapset))
+	    if (2 > Vect_open_old_head(&Map, vect_name, mapset))
 		G_fatal_error(_("Unable to open vector map <%s> on topological level"),
 			      vect_name);