Fix Equihash state initialisation in miner
Fix Equihash state initialisation in miner

After a new block is found or after a few nonces have been tried (currently
after every nonce), the miner checks for global changes. If any of these are
triggered, a new block is built from scratch, which re-initialises the Equihash
input. But if none of the checks are triggered, the miner just updates nTime and
continues mining - without updating the Equihash input to account for the new
block header. This bugfix corrects the behaviour by regenerating the Equihash
input in both situations.

aniemerg/zcash,aniemerg/zcash,loxal/zcash,CTRoundTable/Encrypted.Cash,nathan-at-least/zcash,CTRoundTable/Encrypted.Cash,loxal/zcash,nathan-at-least/zcash,CTRoundTable/Encrypted.Cash,CTRoundTable/Encrypted.Cash,bitcoinsSG/zcash,nathan-at-least/zcash,nathan-at-least/zcash,nathan-at-least/zcash,aniemerg/zcash,loxal/zcash,CTRoundTable/Encrypted.Cash,loxal/zcash,aniemerg/zcash,bitcoinsSG/zcash,CTRoundTable/Encrypted.Cash,aniemerg/zcash,bitcoinsSG/zcash,bitcoinsSG/zcash,aniemerg/zcash,bitcoinsSG/zcash,loxal/zcash,bitcoinsSG/zcash,nathan-at-least/zcash,loxal/zcash