fix timer for timeouts

tests/removeserver.lua

@@ -9,6 +9,15 @@ local wskt = socket.bind("*", 0)
 local whost, wport = wskt:getsockname()
 wport = tonumber(wport)
 
+-- set up a timeout to not hang on failure
+local timeout_timer = copas.timer.new {
+  delay = 10,
+  callback = function()
+      print("timeout!")
+      os.exit(1)
+  end
+}
+
 local connection_handler = function(cskt)
   print(tostring(cskt).." ("..type(cskt)..") received a connection")
   local data, _, partial = cskt:receive()
@@ -38,13 +47,7 @@ copas.addthread(function()
       trigger_it(i)
       copas.pause(0.1)
    end
-end)
-
--- set up a timeout to not hang on failure
-copas.addthread(function()
-   copas.pause(10)
-   print("timeout!")
-   os.exit(1)
+   timeout_timer:cancel()
 end)
 
 copas.loop()