Add id attribute to the installer warning

index.php

@@ -232,7 +232,7 @@ if (empty($RCMAIL->user->ID)) {
 
     // check if installer is still active
     if ($RCMAIL->config->get('enable_installer') && is_readable('./installer/index.php')) {
-        $OUTPUT->add_footer(html::div(array('style' => "background:#ef9398; border:2px solid #dc5757; padding:0.5em; margin:2em auto; width:50em"),
+        $OUTPUT->add_footer(html::div(array('id' => 'login-addon', 'style' => "background:#ef9398; border:2px solid #dc5757; padding:0.5em; margin:2em auto; width:50em"),
             html::tag('h2', array('style' => "margin-top:0.2em"), "Installer script is still accessible") .
             html::p(null, "The install script of your Roundcube installation is still stored in its default location!") .
             html::p(null, "Please <b>remove</b> the whole <tt>installer</tt> folder from the Roundcube directory because