debian zoneinfo link fix

[Jakob Østergaard]

Hello again Attila,

> On 16 Nov 2015, at 18:45, Attila Lendvai <attila at lendvai.name> wrote:
> 
>> I think this would be problematic as symlinks are widely used inside zoneinfo for “aliases”; e.g.
> 
> that part of the code only goes through the zone names. later on the
> symlinks are resolved when the file contents are needed.
> 
> i've recorded my proposed fix that works for me here on debian 8, but
> i don't have the commit bit, so see this PR:
> 

Thanks a lot for your explanation and patience!

/ jakob