Change Details

`'doc'` is listed twice in the `$mimes` array. Remove one entry.

`'doc'` is listed twice in the `$mimes` array. Remove one key. The second key was also removed in https://github.com/PHPMailer/PHPMailer/commit/6f919df65e80023fce4eab58832b6035b4a41935.

`'doc'` is listed twice in the `$mimes` array. Remove one entrykey. The second key was also removed in https://github.com/PHPMailer/PHPMailer/commit/6f919df65e80023fce4eab58832b6035b4a41935.