d.rgb: more gui sections

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@49477 15284696-431f-4ddb-bdfa-cd5b030d7da7

display/d.rgb/main.c

@@ -60,7 +60,8 @@ int main(int argc, char **argv)
     flag_n = G_define_flag();
     flag_n->key = 'n';
     flag_n->description = _("Make null cells opaque");
-
+    flag_n->guisection = _("Null cells");
+    
     for (i = 0; i < 3; i++) {
 	char buff[80];