13
in edituser.php, change the following line
$email_text = new XoopsFormText("", "email", 30, 60, $xoopsUser->getVar("email"));
to
$email_text = new XoopsFormLabel("", $xoopsUser->getVar("email"));
and around line 190, comment out the following line
$edituser->setVar("email", $email);
so it will look like
//$edituser->setVar("email", $email);
sorry, I have not tested this, but hope this works