docs: Avoid mentioning deprecated option
docs: Avoid mentioning deprecated option

Avoid using the deprecated option legacy-host-allows-world in the
upgrade documentation.

Signed-off-by: Joe Stringer <16a9a54ddf4259952e3c118c763138e83693d7fd@cilium.io>

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