Cannot fork in jruby -> cannot daemonize -> handle gracefully

When trying to daemonize the standalone in JRuby, print to stderr and exit 1 as we cannot fork

I did try spoon e.g. https://gist.github.com/ik5/448884/raw/2d945080143a2682dc6ff1862013217265262f8e/daemon.rb but not https://github.com/nicobrevin/jruby-jsvc