Fixes #8744. Makes sure script transport abort method actually remove…

…s the script tag even if readyState exists.

src/ajax/script.js

@@ -53,7 +53,7 @@ jQuery.ajaxTransport( "script", function(s) {
 				// Attach handlers for all browsers
 				script.onload = script.onreadystatechange = function( _, isAbort ) {
 
-					if ( !script.readyState || /loaded|complete/.test( script.readyState ) ) {
+					if ( isAbort || !script.readyState || /loaded|complete/.test( script.readyState ) ) {
 
 						// Handle memory leak in IE
 						script.onload = script.onreadystatechange = null;