i.rectify: use standardized options (https://trac.osgeo.org/grass/ticket/2409)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@62975 15284696-431f-4ddb-bdfa-cd5b030d7da7

imagery/i.rectify/main.c

@@ -124,7 +124,7 @@ int main(int argc, char *argv[])
     val->description = _("Rectification polynomial order (1-3)");
 
     tres = G_define_option();
-    tres->key = "res";
+    tres->key = "resolution";
     tres->type = TYPE_DOUBLE;
     tres->required = NO;
     tres->description = _("Target resolution (ignored if -c flag used)");