i haven't been able to contact the FTP server this morning.

i added support for getting updates from the HTTP server (https://android-review.googlesource.com/57332) but FTP is still the preferred method because:

1. you can get a directory listing via FTP but not HTTP, so if you miss a couple of changes, my script can't take you through the intermediates so the git history remains complete.

2. you can't get the .asc files via HTTP, so no verification.

if HTTP is the preferred download method going forward, could we get .asc files on there and have directory listings turned on for the releases directory?

 --elliott (Android tzdata maintainer)