pkg/option: return error in case validation of IPv4NativeRoutingCIDR fail
pkg/option: return error in case validation of IPv4NativeRoutingCIDR fail

Fixes: e7d4f5c6af7d ("daemon: validate IPv4NativeRoutingCIDR value in DaemonConfig")
Signed-off-by: André Martins <bc9800b9d52a24cce72a73dd528afed53f10e5fc@cilium.io>

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