TripPin OData v4 Sample Service: Bug in Batch support

Hi!

When sending the following batch request:

POST http://services.odata.org/TripPinRESTierService/(S(44nbzk0kapmsdmankuj0auq0))/$batch

OData-Version:4.0
Content-Type:multipart/mixed; boundary=batch_id-1486480047107-5

--batch_id-1486480047107-5
Content-Type:application/http
Content-Transfer-Encoding:binary

GET Airlines?$skip=0&$top=100 HTTP/1.1
Accept:application/json;odata.metadata=minimal;IEEE754Compatible=true
Accept-Language:de-DE
Content-Type:application/json;charset=UTF-8;IEEE754Compatible=true
--batch_id-1486480047107-5--

... I get the following error response, instead of the requested data:

--batchresponse_c8665a96-5705-4304-ac6c-db090c6b5d47
Content-Type: application/http
Content-Transfer-Encoding: binary

HTTP/1.1 404 Not Found
Content-Type: application/json; charset=utf-8

{"Message":"No HTTP resource was found that matches the request URI 'http://services.odata.org/TripPinRESTierService/(S(44nbzk0kapmsdmankuj0auq0))/Airlines?$skip=0&$top=100'."}
--batchresponse_c8665a96-5705-4304-ac6c-db090c6b5d47--

Reproduce the batch request shown in the issue against the TripPinRESTierService $batch endpoint and compare the 404 response with the requested Airlines data. Trace how the sample service handles the batch request and verify that the same request returns the requested data instead of a 404.