修改《角色发生变化时分班人数不对》bug

Signed-off-by: alan <547533434@qq.com>

app/controllers/members_controller.rb

@@ -217,6 +217,7 @@ class MembersController < ApplicationController
             joined.each do |join|
               join.delete
             end
+            @member.course_group_id = 0
           end
           if role.allowed_to?(:is_manager)
             @courseInfo = CourseInfos.new(:user_id => @member.user_id, :course_id => @course.id)