docs: clarify upgrade impact for clients using an egress gateway
docs: clarify upgrade impact for clients using an egress gateway

Signed-off-by: Gilberto Bertin <e45dca12016e9fd4d68d2c7903502c5e1a1f4f1b@isovalent.com>

cilium/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium,cilium/cilium,michi-covalent/cilium,michi-covalent/cilium,michi-covalent/cilium,cilium/cilium