update libtorrent-rasterbar to v0.16.16

0.16.16 release

- add missing add_files overload to the python branding
- improve error handling in http gunzip
- fix debug logging for banning web seeds
- improve support for de-selected files in full allocation mode
- fix dht_bootstrap_alert being posted
- SetFileValidData fix on windows (prevents zero-fill)
- fix minor lock_files issue on unix