Do not reply with Allow-Origin '*' for null Origin

[g-p-g]

See issue sockjs/sockjs-node#177

factory.py should be modified similarly to:

   ...
    def setBaseHeaders(self, request, cookie=True):
        origin = request.getHeader("Origin")
        headers = request.getHeader('Access-Control-Request-Headers')
        if origin is None: #or origin == "null":
            origin = "*"
   ...

[ghost]

I have this problem too, @DesertBus please fix issue.

[Lir10]

+1 for fixing

[luxaritas]

+1, would like to be able to run my app without serving