lib: revert to using a pipe for irc_bot_post Using a signal is discouraged and requires the bot to setup a dummy handler. Also protect the call to irc_bot_post to be fully threadsafe.

[Unit]
Description=IRC Client Daemon
After=network.target

[Service]
ExecStart=@PATH@
User=@IRCCD_WITH_UID@
Group=@IRCCD_WITH_GID@

[Install]
WantedBy=multi-user.target