bug#14890: Wrong hash for tzdata

[Andreas Enge]

$ guix build tzdata --no-substitutes -S

...
starting download of `/nix/store/gryg2h8lp3s8cc4zgxw14yn7d0wgc9lq-
tzdata2013d.tar.gz' from `http://www.iana.org/time-
zones/repository/releases/tzdata2013d.tar.gz'...
http://www.iana.org/.../tzdata2013d.tar.gz      100.0% of 213.8 KiB
output path `/nix/store/gryg2h8lp3s8cc4zgxw14yn7d0wgc9lq-
tzdata2013d.tar.gz' should have sha256 hash 
`08jzd8y2xkgd89wqrv3835pqr48yjabaczxr2rmg42zaykr11an0', instead has 
`011v63ppr73vhjgxv00inkn5pc7z48i8lhbapkpdq3kfczq9c76d'
...

According to the iana web page, the file was released on July 5, while the 
update of the package dates from July 7.

Andreas