unicorn: fix path to pid file

config/unicorn.rb.orig

@@ -15,7 +15,7 @@ timeout 30
 #listen "127.0.0.1:8080"  # listen to port 8080 on the loopback interface
 listen "/tmp/gitlab.socket"
-pid "#{app_dir}/pids/unicorn.pid"
+pid "#{app_dir}/tmp/pids/unicorn.pid"
 stderr_path "#{app_dir}/log/unicorn.stderr.log"
 stdout_path "#{app_dir}/log/unicorn.stdout.log"