Fix SQL query in Register class to ensure proper color assignment during user registration

include/register.php

@@ -64,13 +64,13 @@ class Register extends Renderer {
         $email = strtolower(trim(filter_input(INPUT_POST, 'email', FILTER_SANITIZE_EMAIL)));
         $encryptedEmail = $this->encode($email, $salt);
         $query = sprintf("INSERT INTO ffajs.`user` (username, password, realname, email, active, save_data_accepted, salt, color_id) "
-                . "VALUES('%s', '%s', '%s', '%s', 0, %d, '%s', (SELECT c.id 
+                . "VALUES('%s', '%s', '%s', '%s', 0, %d, '%s', COALESCE((SELECT c.id 
                             FROM color c 
                             left join `user` u
                             on u.color_id = c.id 
                             where u.id is null
                             order by rand()
-                            limit 1))",
+                            limit 1), 1))",
                 strtolower(trim(filter_input(INPUT_POST, 'username', FILTER_SANITIZE_STRING))),
                 password_hash(filter_input(INPUT_POST, 'password', FILTER_SANITIZE_STRING), PASSWORD_DEFAULT),
                 $encryptedName,