Correct nodle's decimals (#110)

Correct the decimals to match what the system.properties rpc returns for [Nodle parachain](https://polkadot.js.org/apps/?rpc=wss%3A%2F%2Fnodle-parachain.api.onfinality.io%2Fpublic-ws#/rpc). Nodle has been using 11 decimals sine November 15th 2021 and even before that it was 12 and not 18.