Remove ZoneDetect .bin file from repository

Remove ZoneDetect .bin file from repository

A Debian maintainer has pointed out that Debian does not permit .bin
files in the packages they create.
The ZoneDetect database file, timezone21.bin has therefore been removed
from the repository.

New users must download the .bin file themself if they require UTC/DST
time offset.

This situation exists because the ZoneDetect developer has not yet put
the source code for the database generator onto GitHub - when that
happens, the database file will be generated by Geeqie (using the
ZoneDetect sources) during the installation procedure.