fix: getHostByName

[lib0xidium]

• added error handling to avoid panics

[lib0xidium]

Hello @mattfarina,

Due to this line: https://github.com/Masterminds/sprig/blob/master/network.go#L11 Helm is failing when getHostByName returns nothing (e.g: due to NXDOMAIN).

The error looks like this:

error calling getHostByName: invalid argument to Intn

because rand.Intn() is called with 0 as an argument.

We should handle this case and return a more descriptive error, both in sprig and helm packages.

Also, returning a random entry from the resolved addresses might introduce confusion. I would prefer/propose to return the whole list of results.