Embeds: After [43593], move the new check to a separate line to avoid `test_js_no_ampersands_in_compiled` failure caused by UglifyJS task.

See #44832.

git-svn-id: https://develop.svn.wordpress.org/trunk@43597 602fd350-edb4-49c9-b593-d223f7449a82

src/js/_enqueues/wp/embed.js

@@ -29,7 +29,12 @@
 
 	window.wp.receiveEmbedMessage = function( e ) {
 		var data = e.data;
-		if ( ! data || ! ( data.secret || data.message || data.value ) ) {
+
+		if ( ! data ) {
+			return;
+		}
+
+		if ( ! ( data.secret || data.message || data.value ) ) {
 			return;
 		}