cherry-pick: home: imp openbsd init script

Closes #4533.

Squashed commit of the following:

commit 48ca9e100619e714eab565273daeb4ee9adb5b74
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Thu Apr 28 20:25:15 2022 +0300

    home: imp openbsd init script

internal/home/service.go

@@ -598,7 +598,7 @@ command_args="-P ${pidfile} -p ${pidfile_child} -f -r {{.WorkingDirectory}}/{{.N
 run_rc_command "$1"
 `
 
-const openBSDScript = `#!/bin/sh
+const openBSDScript = `#!/bin/ksh
 #
 # $OpenBSD: {{ .SvcInfo }}