Revert "Force restart radvd on TZ change; closes #1551"

This reverts commit 36af267d.
Looks like dhcp restart already does this by default now...

src/www/system_general.php

@@ -133,8 +133,6 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
     }
 
     if (count($input_errors) == 0) {
-        $timezone_changed = $config['system']['timezone'] != $pconfig['timezone'];
-
         $config['system']['hostname'] = $pconfig['hostname'];
         $config['system']['domain'] = $pconfig['domain'];
         $config['system']['timezone'] = $pconfig['timezone'];
@@ -231,11 +229,6 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
         system_timezone_configure();
         filter_configure();
 
-        if ($timezone_changed) {
-            /* services that have trouble with changing time zones */
-            services_radvd_configure();
-        }
-
         header(url_safe('Location: /system_general.php?savemsg=%s', array(get_std_save_message(true))));
         exit;
     }