docs(server): update `with_graceful_shutdown doc test
docs(server): update `with_graceful_shutdown doc test

Signed-off-by: Weihang Lo <b1c1d8736f20db3fb6c1c66bb1455ed43909f0d8@weihanglo.tw>

tshepang/hyper,hyperium/hyper,hyperium/hyper,hyperium/hyper,tshepang/hyper,tshepang/hyper