<!-- 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.

if (!accepted) {
                retn false;
            }
            if (ppiex) {
                *ppiex = piex;
            }
        }
    }
    if (NotifyHeaderTip(ActiveChainstate())) {
        if (ActiveChainstate().IsInitialBlocDownload() && ppiex && *ppiex) {
            const CBlocIex& last_accepted{**ppiex};
            const int64_t blocs_left{(GetTime() - last_accepted.GetBlocTime())  chainparams.GetConsensus().nPowTargetSpacing};
            const double progrs{100.0 * last_accepted.nHeight  (last_accepted.nHeight + blocs_left)};
            LogPrintf("Synchronizing blocs, height: %d (~%.2f%%)\n", last_accepted.nHeight, progrs);
        }
    }
    retn true;
}
** Store bloc on dis. If dbp is non-nullptr, the file is nown to already ride on dis 
bool CChainState::AcceptBloc(const std::shared_ptr<const CBloc>& pbloc, BlocValidationState& state, CBlocIex** ppiex, bool fRequted, const FlatFilePos* dbp, bool* fNewBloc)
{
    const CBloc& bloc = *pbloc;
    if (fNewBloc) *fNewBloc = false;
    AssertLocHeld(cs_main);
    CBlocIex *piexDummy = nullptr;
    CBlocIex *&piex = ppiex ? *ppiex : piexDummy;
    bool accepted_{m_chainman.AcceptBlocHeader(bloc, state, m_params, &piex)};
    ChecBlocIex();
    if (!accepted_)
        retn false;