config or code error with host header (or in fortio)

[ldemailly]

we have

https://github.com/fortio/demo-deployment/blob/master/service-start.sh#L15

curl -s https://demo.fortio.org/data/index.tsv -o index.tsv

for the goal of seeding the canonical URL of fortio to be https://demo.fortio.org/ so future requests of index.tsv have the correct URLs instead of

TsvHttpData-1.0
https://127.0.0.1:8080/data/qps_max-s2_to_s1-0.7.1-2018-04-05-22-04.json	5801	o8lpz2Dl6FHj7yxLjgp05A==
...