Change user agent to contain additional information
We should add additional information to user agent. Currently we only report updater version but it is common to also report the OS version, kernel version and network software version. This should help us to discover problematic clients and detect if some combination of software is not failing because of our server configuration.
Current user agent contains only updater version in following format: "Turris Updater/" UPDATER_VERSION
I suggest to append additional information in standard form: "Turris Updater/" UPDATER_VERSION (ADD1; ADD2)
Additional information should be:
- Version and name of distribution
- Architecture and kernel version and name
- Version of libcurl