Log Message:
libfilezilla: update to 0.17.1.

0.17.1 (2019-06-21)

+ Added support for detached signatures
- Fixed crash if using the system trust store

0.17.0 (2019-06-17)

+ libfilezilla now requires C++17
+ Changed a lot of functions to use std::string_view
+ Added fz::socket_layer as base class for layers on top of sockets
+ Added fz::tls_layer, a Transport Layer Security layer, requiring GnuTLS 3.5.7 \ 
or later
+ Added fz::translate for gettext-style translatable strings. GNU Gettext is now \ 
a built-time (but not runtime) dependency
+ Added fz::bitscan and fz::bitscan_reverse to get the index of least and most \ 
significant bit set
+ Added fz::logger_interface as a base for logging system
- *nix: Small speed-up of fz::local_filesys through the use of fstatat()