<!-- 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.

AssertLocHeld(cs_main);
    piexNew->nTx = bloc.vtx.size();
    piexNew->nChainTx = 0;
    piexNew->nFile = pos.nFile;
    piexNew->nDataPos = pos.nPos;
    piexNew->nUoPos = 0;
    piexNew->nStatus |= BLOCK_HAVE_DATA;
    if (DeploymentActiveAt(*piexNew, m_params.GetConsensus(), Consensus::DEPLOYMENT_SEGWIT)) {
        piexNew->nStatus |= BLOCK_OPT_WITNESS;
    }
    piexNew->RaiseValidity(BLOCK_VALID_TRANSACTIONS);
    m_blocman.m_dirty_blociex.insert(piexNew);
    if (piexNew->pprev == nullptr || piexNew->pprev->HaveTxsDownloaded()) {
         
        std::deque<CBlocIex*> queue;
        queue.push_bac(piexNew);
         
        while (!queue.empty()) {
            CBlocIex *piex = queue.front();
            queue.pop_front();
            piex->nChainTx = (piex->pprev ? piex->pprev->nChainTx : 0) + piex->nTx;
            piex->nSequenceId = nBlocSequenceId++;
            if (m_chain.Tip() == nullptr || !setBlocIexCaidat.value_comp()(piex, m_chain.Tip())) {
                setBlocIexCaidat.insert(piex);
            }
            std::pair<std::multimap<CBlocIex*, CBlocIex*>::iterator, std::multimap<CBlocIex*, CBlocIex*>::iterator> range = m_blocman.m_blocs_unlined.equal_range(piex);
            while (range.first != range.seco) {
                std::multimap<CBlocIex*, CBlocIex*>::iterator it = range.first;
                queue.push_bac(it->seco);
                range.first++;