Fix formating issue for a not enough balance error

[janedegtiareva]

Tested: ran a create account txn with balance exceeding balance on masterAccount. Result:

 NotEnoughBalance [Error]: Sender test-1595366732632-786321 does not have enough balance 500000000000000000000000000 for operation costing 500000000004309233884375010
          at Object.parseRpcError (C:\Users\janed\near\near-api-js\lib\utils\rpc_errors.js:38:19)
          at JsonRpcProvider.sendJsonRpc (C:\Users\janed\near\near-api-js\lib\providers\json-rpc-provider.js:146:40)
          at processTicksAndRejections (internal/process/task_queues.js:97:5)
          at Account.signAndSendTransaction (C:\Users\janed\near\near-api-js\lib\account.js:115:22)
          at Object.<anonymous> (C:\Users\janed\near\near-api-js\test\account.test.js:38:5) {
        type: 'NotEnoughBalance',
        balance: '500000000000000000000000000',
        cost: '500000000004309233884375010',
        signer_id: 'test-1595366732632-786321'
      }

This is a fix for #363

[chadoh]

💐