S3 upload broken

Hi, I have been using the static-porter plugin. thankyou its really quite useful.
I thought I would share a bug i had with the signed header for AWS uploads failing.
line 1264 changes the case of the entry ‘Content-Type’ and invalidates the signed header. Commenting this line out seems to fix the issue.

     $content_type = static_porter_guess_mime($file_path);
        $headers = static_porter_aws_sigv4('PUT', $host, $uri, $region, 's3', $body, [
            'content-type' => $content_type,
        ], $access_key, $secret_key);
   //     $headers['Content-Type'] = $content_type;

        $response = wp_remote_request('https://' . $host . $uri, [
            'method'  => 'PUT',
            'headers' => $headers,
            'body'    => $body,
            'timeout' => 60,
        ]);