wspr: Remove more uses of ServerContext as context.
wspr: Remove more uses of ServerContext as context.

Change-Id: Ibeced2b03f638cb4eab1e6af431ccfd7a51eab5e
MultiPart: 2/2

vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref,vanadium/go.ref