SSL en Issuu PDF Sync

functions.php

<?php

function emg_magazine_embed_ssl_compatible( $content ) {
	if ( 'magazine' === get_post_type() ) {
		// Fix Issuu PDF Sync SSL link
		// @see https://plugins.trac.wordpress.org/browser/issuu-pdf-sync/tags/3.1/classes/shortcodes.php#L75
		$content = str_replace( 'http://static.issuu.com/', 'https://static.issuu.com/', $content );	
	}

	return $content;
}

add_filter( 'the_content', 'emg_magazine_embed_ssl_compatible', 99 );