Clean up stale pid files on start

Signed-off-by: Andrej Shadura <andrew.shadura@collabora.co.uk>

docker/docker-entrypoint.sh

 #!/bin/sh
 
 # Make sure there are no stale files from previous runs
-rm -rfv /run/*
+rm -rfv /run/* /var/cache/obs/tmp/pids/*
 mkdir -m a=rwxt /run/lock
 
 /opt/configure-db.sh