support bc height in v8 BEs
support bc height in v8 BEs

bitpay/bitcore-wallet-service,bitjson/bitcore,bitpay/bitcore,bitjson/bitcore,bitjson/bitcore,martindale/bitcore,bitpay/bitcore-wallet-service,martindale/bitcore,bitpay/bitcore,bitpay/bitcore,martindale/bitcore,bitpay/bitcore,martindale/bitcore,bitjson/bitcore