When the config contains a DictOpt that accepts integer keys, the Guru
Meditation Report fails to serialize. Even if current OpenStack code
might not contain such dicts, it's possible that downstream add such
options. Therefore, we change the code to support both dicts with only
integer keys and - just in case - mixed-key dicts.
Change-Id: I44343a8c306c96fc8dc078a76e744cf8b897d8d8
68bc329964