Hello Nadav,
the link for the sitemap is correct, can be used in SEF or non-SEF mode:
http://edoula.me/en/component/jmap/sitemap/xml/
http://edoula.me/index.php?option=com_jmap&view=sitemap&format=xml&lang=en
I checked both links opening in my browser but the XML sitemap is correct, so the error given by GWT is very weird.
If GWT detects an HTML page submitting the above links, ensure that there are no bots blocks, firewall, etc that redirects Google Bot to an HTML page such as CAPTCHA verifications or similar.
John
