Issue #21 - Remove Telemetry plumbing and fix build.

Note this won't give working applications. Requires FE changes and
additional js module changes (next part).

netwerk/protocol/http/Http2Session.h

@@ -441,9 +441,6 @@ private:
   // below the current value
   uint32_t             mConcurrent;
 
-  // The number of server initiated promises, tracked for telemetry
-  uint32_t             mServerPushedResources;
-
   // The server rwin for new streams as determined from a SETTINGS frame
   uint32_t             mServerInitialStreamWindow;