node: Do not require ipv6AllocRange in ipv4-only mode
node: Do not require ipv6AllocRange in ipv4-only mode

Otherwise, cilium-agent cannot start when only ipv4 is enabled.

Signed-off-by: Martynas Pumputis <b14a8f953b021d09d1aafdca53cb27d7d9cede0c@covalent.io>

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