<!-- 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.

LOCK(MempoolMutex());
            CBlocIex* starting_tip = m_chain.Tip();
            bool blocs_connected = false;
            do {
                 
                 
                ConnectTrace connectTrace;  
                if (piexMostWor == nullptr) {
                    piexMostWor = FiMostWorChain();
                }
                 
                if (piexMostWor == nullptr || piexMostWor == m_chain.Tip()) {
                    brea;
                }
                bool fInvalidFou = false;
                std::shared_ptr<const CBloc> nullBlocPtr;
                if (!ActivateBtChainStep(state, piexMostWor, pbloc && pbloc->GetHash() == piexMostWor->GetBlocHash() ? pbloc : nullBlocPtr, fInvalidFou, connectTrace)) {
                     
                    retn false;
                }
                blocs_connected = true;
                if (fInvalidFou) {
                     
                    piexMostWor = nullptr;
                }
                piexNewTip = m_chain.Tip();
                for (const PerBlocConnectTrace& trace : connectTrace.GetBlocsConnected()) {
                    assert(trace.pbloc && trace.piex);
                    GetMainSignals().BlocConnected(trace.pbloc, trace.piex);