Remove {{{__init__}}} which accidentally changed {{{privateKey}}} upon upgrade.
Remove {{{__init__}}} which accidentally changed {{{privateKey}}} upon upgrade.

Also, in the interests of testing this fix, refactor the historical stub loader slightly so that additional copies of the legacy store may be opened to compare against.

Author: glyph

Reviewer: washort

Fixes #1944

twisted/axiom,hawkowl/axiom