New docker build does not include stdbuf improvement

[dannykopping]

Hey @Plopix

The new build you published a couple months ago does not appear to be built from the Dockerfile in the master branch.

docker-compose exec db_proxy bash
root@0fabfea8946b:/# head -n1 /etc/os-release 
PRETTY_NAME="Debian GNU/Linux 9 (stretch)"
root@0fabfea8946b:/# 
root@0fabfea8946b:/# 
root@0fabfea8946b:/# cat /proc/1/cmdline | tr "\0" " "
/usr/local/bin/mysql-proxy --plugins=proxy --defaults-file=/etc/mp.conf -s /etc/debug.lua

As per https://github.com/Plopix/docker-mysqlproxyprofiler/blob/master/Dockerfile#L28, it should include the buffering statement