D2435: commitextras: fix on Python 3 by using sysstrs for __dict__ ops

[indygreg (Gregory Szorc)]

indygreg accepted this revision.
indygreg added a comment.
This revision is now accepted and ready to land.


  That `__dict__` usage is... special.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D2435

To: durin42, #hg-reviewers, indygreg
Cc: indygreg, mercurial-devel