Delegators Loading: Error out when full Account History is not available

[eonwarped]

I thankfully wasn't bitten by this, but recently it seems there are plenty of nodes that are not retaining full account history (understandably). I saw there's a recent update to show a warning in the logs, but perhaps it should add messaging saying: "switch to a full node to load delegators". I also think that if this error condition happens, the bot should crash out completely, otherwise it will be chugging along in a state in which the delegator file is completely corrupted.