Update refresh-token-grant-type.js

[Zireael]

For consistency shouldn't client.id be client.clientId? in: if (token.client.id !== client.id) { throw new InvalidGrantError('Invalid grant: refresh token is invalid'); } Keeping old format with && switch for backwards compatibility: if ((token.client.id !== client.id) && (token.client.id !== client.clientId)) { throw new InvalidGrantError('Invalid grant: refresh token is invalid'); }