mod_auth_http_async: Update documentation The required async APIs were included in 0.10.0, but at the time of this writing we only consider 0.12.x and later supported. The fallback sync API would have made it work with even earlier versions, but I don't remember specifically and it doesn't matter.

This module authenticates server-to-server connections by looking for an already established connection that uses the exact same certificate, reusing
the earlier validation results and letting Prosody skip performing slower validation methods such as [POSH][mod_s2s_auth_posh] twice.