Revert "[java] don't mark Haxe threads as daemon threads (fixes #8131)"

This reverts commit 2ddab520561686c2705c61fa86d92dafd7aef990.

std/java/_std/sys/thread/Thread.hx

@@ -120,5 +120,6 @@ private class HaxeThread extends java.lang.Thread
 		super();
 		threadObject = hxThread;
 		runFunction = run;
+		setDaemon(true);
 	}
 }