fix(xo-server-audit/_exportRecords): dont return 200 on failure

See ec899be3b

CHANGELOG.unreleased.md

@@ -32,5 +32,6 @@
 >
 > In case of conflict, the highest (lowest in previous list) `$version` wins.
 
+- xo-server-audit patch
 - xen-api patch
 - xo-server patch

packages/xo-server-audit/src/index.js

@@ -208,7 +208,7 @@ class AuditXoPlugin {
     return this._xo
       .registerHttpRequest(
         (req, res) => {
-          res.writeHead(200, {
+          res.set({
             'content-disposition': 'attachment',
             'content-type': 'application/json',
           })