mod_pubsub_serverinfo: Warm-up opt-in cache By warming up the cache that contains the opt-in data, the first publication has a better chance of including domain names for remote domains that opt-in. Without this change, those domains are named only after the _second_ publication, which can take a while. New users are likely thrown off by that.

module:set_global();

local traceback = require "util.debug".traceback;

require"util.signal".signal(module:get_option_string(module.name, "SIGUSR1"), function ()
	module:log("info", "Received SIGUSR1, writing traceback");
	local f = io.open(prosody.paths.data.."/traceback.txt", "a+");
	f:write(traceback(), "\n");
	f:close();
end);