mmdb-convert.py do not work on windows
```
d:\Downloads>e:\dev\python-3.4.3.amd64\python.exe mmdb-convert.py GeoIP2-Country.mmdb
Traceback (most recent call last):
File "mmdb-convert.py", line 465, in <module>
write_geoip_file('geoip', metadata, the_tree, dump_item_ipv4, fmt_item_ipv4)
File "mmdb-convert.py", line 447, in write_geoip_file
time.strftime('%B %-d %Y', time.gmtime(build_epoch)))
ValueError: Invalid format string
```
**Trac**:
**Username**: cntor
issue