degesch: get rid of Lua timer hooks

Since they were the exception and have been replaced with the async API.

plugins/degesch/auto-rejoin.lua

@@ -32,6 +32,7 @@ degesch.setup_config {
 	},
 }
 
+async, await = degesch.async, coroutine.yield
 degesch.hook_irc (function (hook, server, line)
 	local msg = degesch.parse (line)
 	if msg.command ~= "KICK" then return line end
@@ -39,9 +40,10 @@ degesch.hook_irc (function (hook, server, line)
 	local who = msg.prefix:match ("^[^!]*")
 	local channel, whom = table.unpack (msg.params)
 	if who ~= whom and whom == server.user.nickname then
-		degesch.hook_timer (function (hook)
+		async.go (function ()
+			await (async.timer_ms (timeout * 1000))
 			server:send ("JOIN " .. channel)
-		end, timeout * 1000)
+		end)
 	end
 	return line
 end)