Apparently pidfile isn't used inside chroot and binding it may cause some weird failures with older systemd.
Fixes https://github.com/NLnetLabs/unbound/issues/138
TemporaryFileSystem=@UNBOUND_CHROOT_DIR@/dev:ro
TemporaryFileSystem=@UNBOUND_CHROOT_DIR@/run:ro
BindReadOnlyPaths=-/run/systemd/notify:@UNBOUND_CHROOT_DIR@/run/systemd/notify
-BindPaths=-@UNBOUND_PIDFILE@:@UNBOUND_CHROOT_DIR@@UNBOUND_PIDFILE@
BindReadOnlyPaths=-/dev/urandom:@UNBOUND_CHROOT_DIR@/dev/urandom
BindPaths=-/dev/log:@UNBOUND_CHROOT_DIR@/dev/log
RestrictAddressFamilies=AF_INET AF_INET6 AF_UNIX