www/template/ajax/users.php: Fix array operation

2024/02/12 18:04:30 [error] 1354432#1354432: *20269 FastCGI sent in stderr: "
PHP Warning:  Cannot assign an empty string to a string offset in /usr/share/bluecherry/www/template/ajax/users.php on line 46
PHP Warning:  implode(): Invalid arguments passed in /usr/share/bluecherry/www/template/ajax/users.php on line 48

Since tmp is used as `$tmp[$id]`, it should be constructed as an array,
not a string. This fixes both warnings.

www/template/ajax/users.php

@@ -39,7 +39,7 @@
             <tbody>
 <?php
         foreach($dvr_users->data as $id => $info){
-            $email_list = ''; $emails = ''; $email = ''; $tmp = '';
+            $email_list = ''; $emails = ''; $email = ''; $tmp = array();
             $emails = explode('|', $info['email']);
             foreach($emails as $id => $email){
                 $email = explode(':', $email);