ITS#9500 fix regression from ITS#8662

mdb_load -a patch broke overwriting with MDB_CURRENT

external/db_drivers/liblmdb/mdb.c

@@ -7867,7 +7867,7 @@ put_sub:
 			xdata.mv_size = 0;
 			xdata.mv_data = "";
 			leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
-			if (flags == MDB_CURRENT) {
+			if ((flags & (MDB_CURRENT|MDB_APPENDDUP)) == MDB_CURRENT) {
 				xflags = MDB_CURRENT|MDB_NOSPILL;
 			} else {
 				mdb_xcursor_init1(mc, leaf);