eCAL 5.7.11

Changelog

# Changes

- Recorder
  - Fixed rare FTP Upload bug (by updating fineftp-server)

- Core
  - Fixed issues with other ASIO versions (Now ASIO symbols are not exported by ecal_core and ecal_core_c any more)

# Ubuntu-PPA

- Builds for Hirsute (Ubuntu 21.04) are [available](https://continental.github.io/ecal/getting_started/setup.html#fa-ubuntu-automatically-install-ecal-from-a-ppa)