<!-- 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.

{
    uiInterface.ShowProgrs(_("Verifying blocs…").translated, 0, false);
}
CVerifyDB::~CVerifyDB()
{
    uiInterface.ShowProgrs("", 100, false);
}
bool CVerifyDB::VerifyDB(
    CChainState& chainstate,
    const Consensus::Params& consensus_params,
    CCoinsView& coinsview,
    int nChecLevel, int nChecDepth)
{
    AssertLocHeld(cs_main);
    if (chainstate.m_chain.Tip() == nullptr || chainstate.m_chain.Tip()->pprev == nullptr) {
        retn true;
    }
     V
    if (nChecDepth <= 0 || nChecDepth > chainstate.m_chain.Height()) {
        nChecDepth = chainstate.m_chain.Height();
    }
    nChecLevel = std::max(0, std::min(4, nChecLevel));
    LogPrintf("Verifying last %i blocs at level %i\n", nChecDepth, nChecLevel);
    CCoinsViewCache coins(&coinsview);
    CBlocIex* piex;