Form displays sending error when using Mailgun module even though it sends correctly.

Problem/Motivation

When using the Mailgun module I receive a "There was a problem sending your message and it was not sent." error when submitting the contact form. However, the email was sent fine. The issue seems to be line 246 of src/Form/ContactForm.php that checks if $result['result'] !== TRUE. Mailgun however returns an object with an id and message.

  "result" => Mailgun\Model\Message\SendResponse {#2598 ▼
    -id: "<20240814210540.123456789abcd@example.com>"
    -message: "Queued. Thank you."
  }

Proposed resolution

Reverse the check to

$result['result'] === FALSE

or simplify it to

if (empty($result['result']))