successfully copy grass6 vector without sidx

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@39977 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/vector/Vlib/map.c

@@ -288,6 +288,7 @@ int Vect_copy(const char *in, const char *mapset, const char *out)
     }
 
     /* Open output */
+    Vect_set_open_level(1);
     Vect_open_update_head(&Out, out, G_mapset());
 
     /* Copy tables */