Implement a release mode action for DbgAssert in `getchaintxsta… (#2090)
Implement a release mode action for DbgAssert in `getchaintxsta… (#2090)

The only way thast assert is triggered is if chainActive.Tip() is
equal to nullptr.
Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited,Justaphf/BitcoinUnlimited,Justaphf/BitcoinUnlimited,Justaphf/BitcoinUnlimited,BitcoinUnlimited/BitcoinUnlimited