[MC-109811] Wrong status code (143) when Minecraft exits after a SIGTERM

If you send SIGTERM to the minecraft server process it exits with a status code of 143.

It should exit with a status code of 0 if stops gracefully.

Steps to reproduce the issue:

root@minecraft:/var/minecraft# java -jar /opt/minecraft/minecraft_server.1.10.2.jar nogui

[ ...wait until server has started, then CTRL-Z to issue an SIGTSTP to suspend the process ]

root@minecraft:/var/minecraft# kill -SIGTERM $(pgrep java)
root@minecraft:/var/minecraft# fg
java -jar /opt/minecraft/minecraft_server.1.10.2.jar nogui
root@minecraft:/var/minecraft# echo $?
143