Configure root_url on load of Site_Url setting

packages/rocketchat-lib/package.js

@@ -34,6 +34,7 @@ Package.onUse(function(api) {
 
 	// Settings
 	api.addFiles('settings/lib/rocketchat.coffee');
+	api.addFiles('settings/lib/onLoadSettings.coffee');
 
 	api.addFiles('settings/server/models/Settings.coffee', 'server');
 	api.addFiles('settings/server/methods.coffee', 'server');

packages/rocketchat-lib/settings/lib/onLoadSettings.coffee

@@ -0,0 +1,5 @@
+RocketChat.settings.onload 'Site_Url', (key, value, initialLoad) ->
+	if value?.trim() isnt ''
+		__meteor_runtime_config__.ROOT_URL = value
+		if Meteor.absoluteUrl.defaultOptions?.rootUrl?
+			Meteor.absoluteUrl.defaultOptions.rootUrl = value