Problem: account not found error message is unclear to user

[leejw51crypto]

when user run like this)
chain-maind tx staking create-validator --from='test' --amount=1cro --pubkey='{"@type":"/cosmos.crypto.ed25519.PubKey","key":"....."}' --moniker="ok" --security-contact="" --chain-id="test2" --commission-rate="0.10" --commission-max-rate="0.20" --commission-max-change-rate="0.01" --min-self-delegation="1" --gas 8000000 --gas-prices 0.1basecro --node $NODE

if test address doesn't have any value,
error is like this

Error: rpc error: code = NotFound desc= rpc error   
desc= account .....    not found: key not found

this error is a little confusing with keyring-backend errors,
can be like this

account ... not found: send fund to create this account, 
and this is not keyring-backend issue