Revert attachment.url back to props.url. Fixes error that prevents inserting media into the editor.

see #24046


git-svn-id: https://develop.svn.wordpress.org/trunk@24009 602fd350-edb4-49c9-b593-d223f7449a82

wp-includes/js/media-editor.js

@@ -191,7 +191,7 @@
 			props = wp.media.string.props( props, attachment );
 			classes = props.classes || [];
 
-			img.src = attachment.url;
+			img.src = props.url;
 			_.extend( img, _.pick( props, 'width', 'height', 'alt' ) );
 
 			// Only assign the align class to the image if we're not printing