Use first og:image declaration if multiple are returned

[khromov]

Reference:
https://wordpress.org/support/topic/content-card-not-displaying-correct-image-on-own-site?replies=1

Example:

...
<meta property="og:image" content="http://margeburkell.com/wp-content/uploads/2015/09/How-to-Get-Started-on-Low-Carb-Checklist.jpg" />
<meta property="og:image" content="http://margeburkell.com/wp-content/uploads/2015/09/90_Days_cropped.png" />
<meta property="og:image" content="http://margeburkell.com/wp-content/uploads/2015/09/2012-to-2014-valentine-party-300x300.jpg" />
<meta property="og:image" content="http://margeburkell.com/wp-content/uploads/2015/08/Marge-Burkell-Trimmed.png" />
...