Fix for publisher logo in AMP WP Plugin

class-amp-post-template.php

/* Edit the class-amp-post-template.php file, either via FTP or within your WordPress Dashboard (go to Plugins > Editor and then select “AMP”) and change this:

if ( $site_icon_url ) {
$metadata['publisher']['logo'] = array(
'@type' => 'ImageObject',
'url' => $site_icon_url,
'height' => self::SITE_ICON_SIZE,
'width' => self::SITE_ICON_SIZE,
);
}

to this:
*/

$metadata['publisher']['logo'] = array(
'@type' => 'ImageObject',
'url' => 'http://domain.com/wp-content/uploads/logo-60.png',
'height' => 60,
'width' => 170,
);