Fix/zone networks empty array

[arnavbhattacharya-NS1]

fix for when a zone is created with the networks=[]. The created zone was being attached Network 0(as it gets added to it by default when no networks field is used)

[fformica]

It worked nicely in my test:

create nil -> []
update [0] -> [0]
update nil -> [0]
update [] -> []

Just a comment

[fformica]

I think we shouldn't make assumptions on the value of Networks, and just force it to nil if NetworkIDs is nil

[fformica]

Interestingly if we do that the first line becomes

create nil -> [0]

Which is the same behaviour we had with NetworksId (it's intended)

[fformica]

@arnavbhattacharya-NS1 can you do this?

Suggested change

	}
	if aux.Networks == nil {
	aux.Networks = &[]int{}
	}
	} else {
	aux.Networks = nil
	}