FEATURE: allow version emails to be disabled globally

app/jobs/scheduled/version_check.rb

@@ -18,9 +18,14 @@ module Jobs
           DiscourseUpdates.updated_at = Time.zone.now
           DiscourseUpdates.missing_versions = json['versions']
 
-          if SiteSetting.new_version_emails and json['missingVersionsCount'] > 0 and prev_missing_versions_count < json['missingVersionsCount'].to_i
+          if  GlobalSetting.new_version_emails and
+              SiteSetting.new_version_emails and
+              json['missingVersionsCount'] > 0 and
+              prev_missing_versions_count < json['missingVersionsCount'].to_i
+
             message = VersionMailer.send_notice
             Email::Sender.new(message, :new_version).send
+
           end
         rescue => e
           raise e unless Rails.env.development? # Fail version check silently in development mode

config/discourse_defaults.conf

@@ -99,4 +99,9 @@ serve_static_assets = false
 sidekiq_workers = 5
 
 # adjust stylesheets to rtl (requires "rtlit" gem)
-rtl_css = false
+rtl_css = false
+
+# notify admin when a new version of discourse is released
+# this is global so it is easier to set in multisites
+# TODO allow for global overrides
+new_version_emails = true