Fix lightbox close button position in vertical mode

script/lightbox.js

@@ -424,7 +424,7 @@
 			return;
 		}
 		else {
-			this.$video.prop('src', null);
+			this.$video.attr('src', '');
 			if($hasVideoNav) $lbContainer.removeClass('lb-video-nav');
         }
 	}