Incorrect SIGN_KEY_DATA_SIZE

[Deinceps]

Class CryptoHelper contains an incorrect constant 'SIGN_KEY_DATA_SIZE', expected 65, current 64

source: https://github.com/EOSIO/eosjs/blob/31ac222bcb1c72830ab3f45c55edddf73805f101/src/eosjs-numeric.ts#L268