chore: sync and leave bug to be fixed

lua/Trans/backend/baidu.lua

@@ -1,6 +1,5 @@
 local M = {}
 
-
 local baidu      = require('Trans').conf.engines.baidu
 local app_id     = baidu.app_id
 local app_passwd = baidu.app_passwd

lua/Trans/backend/init.lua

@@ -1,7 +1,9 @@
 return setmetatable({}, {
     __index = function(t, k)
         local res, engine = pcall(require, [[Trans.backend.]] .. k)
-        assert(res, [[No such Backend: ]] .. k)
+        if not res then
+            error([[Fail to load backend: ]] .. k .. '\n  ' .. engine)
+        end
         t[k] = engine
         return engine
     end