Fix /etc/localtime wrong on Ubuntu 12.04.2

Applying this module on Ubuntu 12.04.2 causes the /etc/localtime to
point to wrong destination:
lrwxrwxrwx 1 root root 20 Mar  4 13:38 localtime -> ../posix/Brazil/East

With this fix the file will be linked to (for example):
lrwxrwxrwx 1 root root 37 Mar  4 10:51 localtime -> /usr/share/zoneinfo/America/Sao_Paulo