[Web] add missing </code> tag in edit/mailbox.twig

data/web/templates/edit/mailbox.twig

@@ -274,7 +274,7 @@
         </div>
         <div class="col-sm-10">
           <p class="text-muted">{{ lang.user.pushover_info|format(mailbox)|raw }}</p>
-          <p class="text-muted">{{ lang.edit.pushover_vars|raw }}: <code>{SUBJECT}</code>, <code>{SENDER}</code>, <code>{SENDER_ADDRESS}</code>, <code>{SENDER_NAME}</code>, <code>{TO_NAME}</code>, <code>{TO_ADDRESS}, <code>{MSG_ID}</code></p>
+          <p class="text-muted">{{ lang.edit.pushover_vars|raw }}: <code>{SUBJECT}</code>, <code>{SENDER}</code>, <code>{SENDER_ADDRESS}</code>, <code>{SENDER_NAME}</code>, <code>{TO_NAME}</code>, <code>{TO_ADDRESS}</code>, <code>{MSG_ID}</code></p>
           <div class="row">
             <div class="col-sm-6 mb-2">
               <label for="token">API Token/Key (Application)</label>