killing command after command-timeout does not kill child processes

[kwibus]

Gucamole plugin will kill start/stop command when they take longer then command-timeout

guacamole-trigger/src/main/java/org/apache/guacamole/guacamoletrigger/auth/Console.java

Lines 72 to 74 in 66b1d29

	// TODO this wont kill desendancs,
	// those will become zombie process in linux if they finish
	process.destroyForcibly ();

But this wont kill children of this process, end if child proces exists when its parent is killed.
Java wont reap it so it can becomes a zombie proces.