server: correct doc regarding unknown handlers and interceptors (#3195)
server: correct doc regarding unknown handlers and interceptors (#3195)


dfawley/grpc-go,stanley-cheung/grpc-go,dfawley/grpc-go,grpc/grpc-go,menghanl/grpc-go,stanley-cheung/grpc-go,menghanl/grpc-go,grpc/grpc-go