D7544: py3: remove incorrect b prefix on second argument to open in subrepo.py

[mharbison72 (Matt Harbison)]

mharbison72 added a comment.


  I don't think this is correct, because `open` is imported from `pycompat` at the top of the file, and that will `sysstr()` the mode.  But this does seem confusing- see D7517 <https://phab.mercurial-scm.org/D7517>.

REPOSITORY
  rHG Mercurial

CHANGES SINCE LAST ACTION
  https://phab.mercurial-scm.org/D7544/new/

REVISION DETAIL
  https://phab.mercurial-scm.org/D7544

To: spectral, #hg-reviewers
Cc: mharbison72, mercurial-devel