C#V2 v2.1.11416

- Update Mbed-TLS lib to 4.0
- Add support for old .NET framework (3.5)
- Improve error reporting if dll is not found
- Fix return value for GetDllArchitecture on Windows ARM
- Fix some timeout with YAPI::PreregisterHub
- Fix redirection handling with IpV6 address
- Fix rare deadlock when network connection is very unstable
