Merge branch 'dev_aliyun' into dev_tj

merge aliyun

app/controllers/courses_controller.rb

@@ -224,7 +224,7 @@ class CoursesController < ApplicationController
         normal_status(0, "成功")
       rescue => e
         uid_logger_error(e.message)
-        tip_exception("课堂更新失败")
+        tip_exception("课堂更新失败,原因: #{e.message}")
         raise ActiveRecord::Rollback
       end
     end

app/controllers/graduation_tasks_controller.rb

@@ -225,7 +225,7 @@ class GraduationTasksController < ApplicationController
       }
       attachment = work.attachments.last
       if attachment
-        o[:downloadUrl] = "https://#{Setting.host_name}/"+download_url(attachment)
+        o[:downloadUrl] = "https://#{edu_setting('host_name')}/"+download_url(attachment)
       end
 
       o