Update OkHttp to 3.12.3.
Update OkHttp to 3.12.3.

yenliangl/bitcoinj,peterdettman/bitcoinj,schildbach/bitcoinj,schildbach/bitcoinj,bitcoinj/bitcoinj,bitcoinj/bitcoinj,natzei/bitcoinj,yenliangl/bitcoinj,peterdettman/bitcoinj,natzei/bitcoinj