vlib: add missing #ifdef (--without-postgres)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@53690 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/vector/Vlib/copy.c

@@ -287,10 +287,12 @@ int copy_nodes(const struct Map_info *In, struct Map_info *Out)
         if (with_z)
             Points->z[0] = z;
         
+#ifdef HAVE_POSTGRES
         if (-1 == V2__write_node_pg(Out, Points)) {
             G_warning(_("Writing node %d failed"), node);
             return 1;
         }
+#endif
     }
 
     Vect_destroy_line_struct(Points);