Get test working when there are multiple dbs supported.
diff --git a/Lib/test/test_whichdb.py b/Lib/test/test_whichdb.py
index d1cac1d..7746329 100644
--- a/Lib/test/test_whichdb.py
+++ b/Lib/test/test_whichdb.py
@@ -28,6 +28,7 @@
             name = module.__name__
             if name == 'dumbdbm':
                 continue   # whichdb can't support dumbdbm
+            test.test_support.unlink(_fname)
             f = module.open(_fname, 'c')
             f.close()
             self.assertEqual(name, whichdb.whichdb(_fname))