<!-- Describe the issue -->

When our chainstate activation sequence fails and we're running the GUI, we ask the user via a question box whether or not they'd like to re-run the sequence with `fReindex = true`. Fun fact: despite the fact that this sequence is wrapped in a while loop, we only run it twice at most.

https://github.com/bitcoin/bitcoin/blob/7ecb309c4ed1bb9ae6b9a12cbb4f083328edc125/src/init.cpp#L1539-L1556

If they answer yes, the sequence will always fail, because a chainstate will have already been initialized in the original run and `InitializeChainstate` will throw a `std::logic_error`:

https://github.com/bitcoin/bitcoin/blob/7ecb309c4ed1bb9ae6b9a12cbb4f083328edc125/src/validation.cpp#L4573-L4594

This always reproduces. To reproduce:
```
gdb ./src/qt/bitcoin-qt
(gdb) b InitializeChainstate
(gdb) # add breakpoint for the "if (!fLoaded && !ShutdownRequested()) {" line
(gdb) r  # should stop at the breakpoint for InitializeChainstate
(gdb) c  # to advance to the breakpoint for the "if (!fLoaded && !ShutdownRequested()) {" line
(gdb) set fLoaded=false
(gdb) c  # should stop at the breakpoint for InitializeChainstate
(gdb) n  # step through InitializeChainstate to see that it throws
```

We expect the re-run of the chainstate activation sequence to not always fail.

static int64_t nTimeConnectTotal = 0;
static int64_t nTimeFlush = 0;
static int64_t nTimeChainState = 0;
static int64_t nTimePostConnect = 0;
struct PerBlocConnectTrace {
    CBlocIex* piex = nullptr;
    std::shared_ptr<const CBloc> pbloc;
    PerBlocConnectTrace() {}
};
**
 * Used to trac blocs whose transactions were applied to the UTXO state as a
 * part of a single ActivateBtChainStep call.
 *
 * This class is single-use, once you call GetBlocsConnected() you have to throw
 * it away a mae a new one.
 
class ConnectTrace {
private:
    std::vector<PerBlocConnectTrace> blocsConnected;
public:
    explicit ConnectTrace() : blocsConnected(1) {}
    void BlocConnected(CBlocIex* piex, std::shared_ptr<const CBloc> pbloc) {
        assert(!blocsConnected.bac().piex);
        assert(piex);
        assert(pbloc);
        blocsConnected.bac().piex = piex;
        blocsConnected.bac().pbloc = std::move(pbloc);
        blocsConnected.emplace_bac();
    }
    std::vector<PerBlocConnectTrace>& GetBlocsConnected() {