go/neo/t/tzodb.py: Fix zhash for Python3

On py3 dict.keys() returns iterator instead of list:

    $ ./tzodb.py zhash
    Traceback (most recent call last):
      File "/home/kirr/src/neo/src/lab.nexedi.com/kirr/neo/go/neo/t/./tzodb.py", line 141, in <module>
        main()
      File "/home/kirr/src/neo/src/lab.nexedi.com/kirr/neo/go/neo/t/./tzodb.py", line 138, in main
        zhash()
      File "/home/kirr/src/neo/src/lab.nexedi.com/kirr/neo/go/neo/t/./tzodb.py", line 59, in zhash
        optv, argv = getopt(sys.argv[2:], "h", ["help", "check=", "bench="] + hashRegistry.keys())
    TypeError: can only concatenate list (not "dict_keys") to list

go/neo/t/tzodb.py

 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-# Copyright (C) 2017-2018  Nexedi SA and Contributors.
+# Copyright (C) 2017-2022  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
@@ -56,7 +56,7 @@ def zhash():
         exit(1)
 
     try:
-        optv, argv = getopt(sys.argv[2:], "h", ["help", "check=", "bench="] + hashRegistry.keys())
+        optv, argv = getopt(sys.argv[2:], "h", ["help", "check=", "bench="] + list(hashRegistry.keys()))
     except GetoptError as e:
         print("E: %s" % e, file=sys.stderr)
         usage(sys.stderr)