backport PR9734 https://github.com/bitcoin/bitcoin/pull/9734/files
41b8821 Add updating of chainTxData to release process (Pieter Wuille)
Tree-SHA512: f7d6e72b19aa83fc4851a9316d6c6a236e0e914d637525cda42c0b15a94543b8072ce67b57d6b12141332a03b64b6c715dff4d61e6e58e0197b22305b35ad65d
(moved for new layout)