[API] Fixed only allow GET logic

data/web/json_api.php

@@ -205,7 +205,7 @@ if (isset($_SESSION['mailcow_cc_role']) || isset($_SESSION['pending_mailcow_cc_u
         function process_get_return($data) {
           echo (!isset($data) || empty($data)) ? '{}' : json_encode($data, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT);
         }
-        if ($_SERVER['REQUEST_METHOD'] === 'GET') {
+        if ($_SERVER['REQUEST_METHOD'] != 'GET') {
           http_response_code(400);
           echo json_encode(array(
               'type' => 'error',