envoy: Fix xDS server start log message
envoy: Fix xDS server start log message

Fixes: #3273

Signed-off-by: Romain Lenglet <b8aabb4b95c817d9df69b6be95b2b94d6b1efe17@covalent.io>

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