don't rely on dict order here

Lib/test/test_gdbm.py

@@ -47,7 +47,7 @@ class TestGdbm(unittest.TestCase):
         all = set(gdbm.open_flags)
         # Test standard flags (presumably "crwn").
         modes = all - set('fsu')
-        for mode in modes:
+        for mode in sorted(modes):
             self.g = gdbm.open(filename, mode)
             self.g.close()