Revert "raise socket error during auth"

This reverts commit 839975415d.

lualib/skynet/socketchannel.lua

@@ -418,12 +418,6 @@ local function block_connect(self, once)
 	if #self.__connecting > 0 then
 		-- connecting in other coroutine
 		local co = coroutine.running()
-		for _, v in ipairs(self.__connecting) do
-			if v == co then
-				-- socket closed during auth (connecting) , See Issue #1513
-				error(socket_error)
-			end
-		end
 		table.insert(self.__connecting, co)
 		skynet.wait(co)
 	else