* Use the RealIP middleware only behind a reverse proxy
* Fix proxy ip source in tests
* Fix test for PR#2087
The PR did not update the test after changing the behavior, but the test still
passed because another condition was preventing the user from being created in
the test.
* Use RealIP even without a trusted reverse proxy
* Use own type for context key
* Fix casing to follow go's conventions
* Do not apply RealIP middleware twice
* Fix IP source in logs
The most interesting data point in the log message is the proxy's IP, but
having the client IP too can help identify integration issues.
