When -blocksonly is set to 1, it interacts with the -walletbroadcast
parameter and sets it to 0 if it has not been set already.This behavior
is not captured by the current documentation, which claims that -blocksonly
does not impact any wallet transactions.
(cherry picked from commit 621e86ee8d0102e2bf41f7656a368083b89b2f83)
Zcash: Excludes max-peer doc changes, since we don't have
block-relay-only peers yet.