docs: small update to getting started with Docker
docs: small update to getting started with Docker

Before this patch, the HTTP headers seen once l7_aware_policy.json is
imported are different than documented (e.g. the server is envoy).

This patch reflect this change in the documentation to better match what
to expect when going through step 9.

Signed-off-by: Alexandre Perrin <60c6d277a8bd81de7fdde19201bf9c58a3df08f4@kaworu.ch>

michi-covalent/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium,tgraf/cilium,michi-covalent/cilium,tklauser/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,cilium/cilium,tgraf/cilium,tgraf/cilium,tklauser/cilium,tklauser/cilium,tgraf/cilium,tklauser/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium