node: Fix panic when node store is not initialized yet
node: Fix panic when node store is not initialized yet

Because node store registration happens in the background, the nodeStore
pointer can still be nil at the time the local node is updated first.

Fixes: 4a7d484af44b ("Daemon: Update Health endpoints IP on localNode.")
Fixes: #5137

Signed-off-by: Thomas Graf <5f50a84c1fa3bcff146405017f36aec1a10a9e38@cilium.io>

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