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
#!/bin/sh
# This scripts is used to install dependencies for
# testing Mercurial. Mainly used by Vagrant (see
# Vagrantfile for details).
export DEBIAN_FRONTEND=noninteractive
apt-get update
apt-get install -y -q python-dev unzip
# run-tests.sh is added by Vagrantfile
chmod +x run-tests.sh