Rigify bugfix: dev tools panel was displayed regardless of mode.

Thanks to Sanc Tuary for the bug report! Bug #35040


git-svn-id: https://svn.blender.org/svnroot/bf-extensions/trunk/py/scripts/addons@4488 96b784f8-4ae3-dd11-aff7-0030488c597c
Merge remote-tracking branch 'remotes/trunk'

* remotes/trunk:
  Rigify bugfix: dev tools panel was displayed regardless of mode.