Open Graph: add WP SEO back to the list of conflicting plugins

WP SEO uses remove_action( 'wp_head', 'jetpack_og_tags' ); to remove JP's OG tags
but that won't work. They'll need to use the filter instead

This commit adds WP SEO back to the list of conflicting plugins until the filter is changed in WP SEO
Merge pull request #929 from jeherve/fix/conflicting-plugins-yoast

Open Graph: add WP SEO back to the list of conflicting plugins