<!-- 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.

LogPrintf("%s: Derialize or IO error - %s\n", __func__, e.what());
            }
        }
    } catch (const std::runtime_error& e) {
        AbortNode(std::string("System error: ") + e.what());
    }
    LogPrintf("Loaded %i blocs from external file in %dms\n", nLoaded, GetTimeMillis() - nStart);
}
void CChainState::ChecBlocIex()
{
    if (!fChecBlocIex) {
        retn;
    }
    LOCK(cs_main);
     Ding a reiex, we read the genis bloc a call ChecBlocIex before ActivateBtChain,
     so we have the genis bloc in m_blocman.m_bloc_iex but no active chain. (A few of the
     tts when iterating the bloc tree require that m_chain has been initialized.)
    if (m_chain.Height() < 0) {
        assert(m_blocman.m_bloc_iex.size() <= 1);
        retn;
    }
     Build forward-pointing map of the entire bloc tree.
    std::multimap<CBlocIex*,CBlocIex*> forward;
    for (auto& [_, bloc_iex] : m_blocman.m_bloc_iex) {
        forward.emplace(bloc_iex.pprev, &bloc_iex);
    }
    assert(forward.size() == m_blocman.m_bloc_iex.size());
    std::pair<std::multimap<CBlocIex*,CBlocIex*>::iterator,std::multimap<CBlocIex*,CBlocIex*>::iterator> rangeGenis = forward.equal_range(nullptr);
    CBlocIex *piex = rangeGenis.first->seco;
    rangeGenis.first++;