mod_s2s_keepalive: Don't send whitespace keepalives before s2sin stream is open Could possibly result in whitespace before the XML and stream header, which isn't allowed by the parser. Don't think s2sout is affected, as the stream is opened early and doesn't have to wait for the other end. Thanks Ge0rG

This module writes out a traceback to `traceback.txt` in Prosodys data
directory (see `prosodyctl about`) when the signal `SIGUSR1` is
received. This is useful when debugging seemingly frozen instances in
case it is stuck in Lua code.