<!-- 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.

return false;
    }
     Either install a handler to notify us when genesis activates, or set fHaveGenesis directly.
     No locking, as this happens before any background thread is started.
    boost::signals2::connection block_notify_genesis_wait_connection;
    if (chainman.ActiveChain().Tip() == nullptr) {
        block_notify_genesis_wait_connection = uiInterface.NotifyBlockTip_connect(std::bind(BlockNotifyGenesisWait, std::placeholders::_2));
    } else {
        fHaveGenesis = true;
    }
#if HAVE_SYSTEM
    const std::string block_notify = args.GetArg("-blocknotify", "");
    if (!block_notify.empty()) {
        uiInterface.NotifyBlockTip_connect([block_notify](SynchronizationState sync_state, const CBlockIndex* pBlockIndex) {
            if (sync_state != SynchronizationState::POST_INIT || !pBlockIndex) return;
            std::string command = block_notify;
            boost::replace_all(command, "%s", pBlockIndex->GetBlockHash().GetHex());
            std::thread t(runCommand, command);
            t.detach(); 
        });
    }
#endif
    std::vector<fs::path> vImportFiles;
    for (const std::string& strFile : args.GetArgs("-loadblock")) {
        vImportFiles.push_back(fs::PathFromString(strFile));
    }
    chainman.m_load_block = std::thread(&util::TraceThread, "loadblk", [=, &chainman, &args] {
        ThreadImport(chainman, vImportFiles, args);
    });
     Wait for genesis block to be processed