message: hide analytics settings if no piwik url
diff: @@ -777,6 +777,8 @@ module.exports = React.createClass({
  },
  _renderAnalyticsControl: function() {
  + if (!SdkConfig.get().piwik) return <div/>;
  +
  return <div>
  <h3>{ _t('Analytics') }</h3>
  <div className="mx_UserSettings_section">
  