竞赛banner跳转链接 setting中配置

app/views/settings/show.json.jbuilder

@@ -37,6 +37,7 @@ json.setting do
   json.subject_banner_url default_setting.subject_banner_url&.[](1..-1)
   json.course_banner_url default_setting.course_banner_url&.[](1..-1)
   json.competition_banner_url EduSetting.get("competition_banner_url").to_s
+  json.competition_banner_href EduSetting.get("competition_banner_href").to_s
   json.moop_cases_banner_url default_setting.moop_cases_banner_url&.[](1..-1)
   json.oj_banner_url default_setting.oj_banner_url&.[](1..-1)