Add site_setting to disable version checks

app/assets/javascripts/admin/routes/admin_dashboard_route.js

@@ -2,11 +2,13 @@
 
   Discourse.AdminDashboardRoute = Discourse.Route.extend({
     setupController: function(c) {
+      if( Discourse.SiteSettings.version_checks ) {
         return Discourse.VersionCheck.find().then(function(vc) {
           c.set('versionCheck', vc);
           return c.set('loading', false);
         });
       }
+    }
   });
 
 }).call(this);

app/assets/javascripts/admin/templates/dashboard.js.handlebars

@@ -1,5 +1,6 @@
 <h3>{{i18n admin.dashboard.welcome}}</h3>
 
+{{#if Discourse.SiteSettings.version_checks}}
   <p {{bindAttr class="priorityClass"}}>
     {{#if loading }}
       {{i18n loading}}
@@ -19,3 +20,4 @@
       </span>
     {{/if}}
   </p>
+{{/if}}

app/models/site_setting.rb

@@ -31,6 +31,7 @@ class SiteSetting < ActiveRecord::Base
   client_setting(:flush_timings_secs, 5)
   client_setting(:supress_reply_directly_below, true)
   client_setting(:email_domains_blacklist, 'mailinator.com')
+  client_setting(:version_checks, true)
 
   # settings only available server side
   setting(:auto_track_topics_after, 300000)

config/locales/server.en.yml

@@ -294,6 +294,7 @@ en:
     supress_reply_directly_below: "Don't show replies button below a post when the reply is directly below"
     allow_index_in_robots_txt: "Site should be indexed by search engines (update robots.txt)"
     email_domains_blacklist: "A pipe-delimited list of email domains that are not allowed. Example: mailinator.com|trashmail.net"
+    version_checks: 'Whether to check for Discourse updates and report them on the admin dashboard.'
 
     port: "If you'd like to specify a port in the URL. Useful in development mode. Leave blank for none."
     force_hostname: "If you'd like to specify a hostname in the URL. Useful in development mode. Leave blank for none."

lib/jobs/version_check.rb

@@ -5,9 +5,11 @@ module Jobs
   class VersionCheck < Jobs::Base
 
     def execute(args)
+      if SiteSetting.version_checks
         json = DiscourseHub.discourse_version_check
         DiscourseUpdates.latest_version = json['latestVersion']
         DiscourseUpdates.critical_update_available = json['criticalUpdates']
+      end
       true
     end