D4170: linelog: fix bytes/str issue in exception raise on Python 3

[durin42 (Augie Fackler)]

durin42 added a comment.


  >   I assume LineLogError is a kind of a ProgrammingError. If it's a user-facing
  >   error, we'll have to convert a message to bytes.
  
  Yep - it should never happen (barring misuse of the API or woefully corrupt linelog files).

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D4170

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