py3: add a missing b'' prefix in contrib/perf.py
# skip-blame because just b'' prefixes
This fixes test-contrib-perf.t on Python 3 which started failing.
Differential Revision: https://phab.mercurial-scm.org/D5421
BasedOnStyle: LLVM
IndentWidth: 8
UseTab: ForIndentation
BreakBeforeBraces: Linux
AllowShortIfStatementsOnASingleLine: false
IndentCaseLabels: false
AllowShortBlocksOnASingleLine: false
AllowShortFunctionsOnASingleLine: false
IncludeCategories:
- Regex: '^<'
Priority: 1
- Regex: '^"'
Priority: 2