<!-- 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.

pos.nFile = nFile;
        pos.nPos = m_blockfile_info[nFile].nSize;
    }
    if ((int)nFile != m_last_blockfile) {
        if (!fKnown) {
            LogPrint(BCLog::BLOCKSTORE, "Leaving block file %i: %s\n", m_last_blockfile, m_blockfile_info[m_last_blockfile].ToString());
        }
        FlushBlockFile(!fKnown, finalize_undo);
        m_last_blockfile = nFile;
    }
    m_blockfile_info[nFile].AddBlock(nHeight, nTime);
    if (fKnown) {
        m_blockfile_info[nFile].nSize = std::max(pos.nPos + nAddSize, m_blockfile_info[nFile].nSize);
    } else {
        m_blockfile_info[nFile].nSize += nAddSize;
    }
    if (!fKnown) {
        bool out_of_space;
        size_t bytes_allocated = BlockFileSeq().Allocate(pos, nAddSize, out_of_space);
        if (out_of_space) {
            return AbortNode("Disk space is too low!", _("Disk space is too low!"));
        }
        if (bytes_allocated != 0 && fPruneMode) {
            m_check_for_pruning = true;
        }
    }
    m_dirty_fileinfo.insert(nFile);
    return true;
}
bool BlockManager::FindUndoPos(BlockValidationState& state, int nFile, FlatFilePos& pos, unsigned int nAddSize)