Extra MtaRailroadStopTimeUpdate

[doc...@gmail.com]

I was getting an error when parsing Metro North GTFS real time feed proto buffer data.

It turns out that each StopTimeUpdate contained two 1005 MtaRailroadStopTimeUpdate structures. The first one has the track and train status and the second empty with length zero. This second structure doesn't show up when converting it to JSON with protoc. While fixed up my parsing code to handle a zero length structure, the extra one adds unnecessary data and may be a technical violation of the specification.

Also the feeds doesn't have any Carriage Details.