Fix Bug #67530 	error_log=syslog ignored

As for Bug #64915
Systemd use --nodaemonize but need to error_log to file or syslog to be honoured
5.6 have fpm_globals.force_stderr
NEWS
Merge branch 'PHP-5.6'

* PHP-5.6:
  NEWS
  5.6 have fpm_globals.force_stderr
  Fix Bug #67530 	error_log=syslog ignored