set_config.py exist if one file is not found.

Found following error, set_config shouldn't exist when file is not found.

ERROR:__main__:Unexpected error:
Traceback (most recent call last):
  File "/usr/local/bin/kolla_set_configs", line 412, in <module>
    main()
  File "/usr/local/bin/kolla_set_configs", line 406, in main
    execute_config_strategy(config)
  File "/usr/local/bin/kolla_set_configs", line 374, in execute_config_strategy
    handle_permissions(config)
  File "/usr/local/bin/kolla_set_configs", line 366, in handle_permissions
    set_perms(os.path.join(root, file_), uid, gid)
  File "/usr/local/bin/kolla_set_configs", line 357, in set_perms
    os.chown(path, uid, gid)
OSError: [Errno 2] No such file or directory: '/var/log/kolla/haproxy/haproxy_latest.log'