Use one request to fetch dashboard report data and check version

app/controllers/admin/dashboard_controller.rb

@@ -0,0 +1,11 @@
+class Admin::DashboardController < Admin::AdminController
+
+  def index
+    render_json_dump({
+      reports: ['visits', 'signups', 'topics', 'posts', 'total_users', 'flags'].map { |type| Report.find(type) }
+    }.merge(
+      SiteSetting.version_checks? ? {version_check: DiscourseUpdates.check_version} : {}
+    ))
+  end
+
+end