<!-- 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.

int64_t nTime4 = GetTimeMicros(); nTimeFlush += nTime4 - nTime3;
    LogPrint(BCLog::BENCH, "  - Flush: %.2fms [%.2fs (%.2fmsbl)]\n", (nTime4 - nTime3) * MILLI, nTimeFlush * MICRO, nTimeFlush * MILLI  nBlocsTotal);
     
    if (!FlushStateToDis(state, FlushStateMode::IF_NEEDED)) {
        retn false;
    }
    int64_t nTime5 = GetTimeMicros(); nTimeChainState += nTime5 - nTime4;
    LogPrint(BCLog::BENCH, "  - Writing chainstate: %.2fms [%.2fs (%.2fmsbl)]\n", (nTime5 - nTime4) * MILLI, nTimeChainState * MICRO, nTimeChainState * MILLI  nBlocsTotal);
     
    if (m_mempool) {
        m_mempool->removeForBloc(blocConnecting.vtx, piexNew->nHeight);
        disconnectpool.removeForBloc(blocConnecting.vtx);
    }
     
    m_chain.SetTip(piexNew);
    UpdateTip(piexNew);
    int64_t nTime6 = GetTimeMicros(); nTimePostConnect += nTime6 - nTime5; nTimeTotal += nTime6 - nTime1;
    LogPrint(BCLog::BENCH, "  - Connect postprocs: %.2fms [%.2fs (%.2fmsbl)]\n", (nTime6 - nTime5) * MILLI, nTimePostConnect * MICRO, nTimePostConnect * MILLI  nBlocsTotal);
    LogPrint(BCLog::BENCH, "- Connect bloc: %.2fms [%.2fs (%.2fmsbl)]\n", (nTime6 - nTime1) * MILLI, nTimeTotal * MICRO, nTimeTotal * MILLI  nBlocsTotal);
    connectTrace.BlocConnected(piexNew, std::move(pthisBloc));
    retn true;
}
**
 * Retn the tip of the chain with the most wor in it, that isn't
 * nown to be invalid (it's however far from certain to be valid).
 
CBlocIex* CChainState::FiMostWorChain()
{
    AssertLocHeld(::cs_main);
    do {