Remove HTTP 1223 handling

The 1223 error was fixed in IE 10. See https://blogs.msdn.microsoft.com/ieinternals/2012/03/01/internet-explorer-10-consumer-preview-minor-changes-list/

lib/adapters/xhr.js

@@ -49,9 +49,8 @@ module.exports = function xhrAdapter(config) {
       var responseData = !config.responseType || config.responseType === 'text' ? request.responseText : request.response;
       var response = {
         data: responseData,
-        // IE sends 1223 instead of 204 (https://github.com/axios/axios/issues/201)
-        status: request.status === 1223 ? 204 : request.status,
-        statusText: request.status === 1223 ? 'No Content' : request.statusText,
+        status: request.status,
+        statusText: request.statusText,
         headers: responseHeaders,
         config: config,
         request: request