Fix transition of allowed headers.

Client is sending Access-Control-Request-Headers, server shall respond with
Access-Control-Allow-Headers.

master/product/Vifib/Tool/VifibRestApiV1Tool.py

@@ -134,10 +134,10 @@ def responseSupport(anonymous=False):
   def outer(fn):
     def wrapperResponseSupport(self, *args, **kwargs):
       self.REQUEST.response.setHeader('Content-Type', 'application/json')
-      allow_headers = self.REQUEST.getHeader('Access-Control-Allow-Headers')
-      if allow_headers:
+      request_headers = self.REQUEST.getHeader('Access-Control-Request-Headers')
+      if request_headers:
         self.REQUEST.response.setHeader('Access-Control-Allow-Headers',
-          allow_headers)
+          request_headers)
       self.REQUEST.response.setHeader('Access-Control-Allow-Origin', '*')
       self.REQUEST.response.setHeader('Access-Control-Allow-Methods', 'DELETE, PUT, POST, '
         'GET, OPTIONS')