Fix title of hostname diagnostics page.

templates/hostnames.php

 <?php
+$this->data['header'] = $this->t('{status:header_diagnostics}');
 $this->includeAtTemplateBase('includes/header.php');
 $this->includeAtTemplateBase('includes/attributes.php');
 

www/admin/hostnames.php

@@ -26,7 +26,6 @@ $attributes['Utilities_selfURL()'] = array(\SimpleSAML\Utils\HTTP::getSelfURL())
 
 $et = new SimpleSAML_XHTML_Template($config, 'hostnames.php');
 
-$et->data['header'] = '{status:header_diagnostics}';
 $et->data['remaining']  = $session->getAuthData('admin', 'Expire') - time();
 $et->data['attributes'] = $attributes;
 $et->data['valid'] = 'na';