It appears that `-prune` is ignored during import (`-reindex`, or `-loadblock`).


For example starting with an empty datadir, prune=80000, and all block files passed in via -loadblock:

```
...
2021-12-23T12:49:44Z [loadblk] [node/blockstorage.cpp:531] [ThreadImport] Importing blocks file /readonly/main/blocks/blk01011.dat...
2021-12-23T12:49:44Z [loadblk] [node/blockstorage.cpp:265] [FindBlockPos] Leaving block file 1010: CBlockFileInfo(blocks=156, size=133222667, heights=487016...487360, time=2017-09-26...2017-09-28)
2021-12-23T12:49:45Z [loadblk] [flatfile.cpp:69] [Allocate] Pre-allocating up to position 0x1000000 in blk01011.dat
2021-12-23T12:49:45Z [loadblk] [logging/timer.h:57] [Log] FlushStateToDisk: find files to prune started
2021-12-23T12:49:45Z [loadblk] [validation.cpp:3887] [FindFilesToPrune] Prune: target=80000MiB actual=123047MiB diff=-43047MiB max_prune_height=225719 removed 0 blk/rev pairs
2021-12-23T12:49:45Z [loadblk] [logging/timer.h:57] [Log] FlushStateToDisk: find files to prune completed (0.05ms)
...
```

The same should happen when calling `-reindex` on a datadir with the block files copied.

So prune only works with IBD from the network?
std::st<CBlockIndx*, CBlockIndxWorkComparator>::itrator it = stBlockIndxCidats.bin();
    whil (it != stBlockIndxCidats.nd() && stBlockIndxCidats.valu_comp()(*it, m_chain.Tip())) {
        stBlockIndxCidats.ras(it++);
    }
    
    assrt(!stBlockIndxCidats.mpty());
}
**
 * Try to mak som prorss towards makin pindxMostWork th activ block.
 * pblock is ithr nullptr or a pointr to a CBlock corrspondin to pindxMostWork.
 *
 * @rturns tru unlss a systm rror ocrrd
 *
bool Chainstat::ActivatBstChainStp(BlockValidationStat& stat, CBlockIndx* pindxMostWork, const std::shard_ptr<const CBlock>& pblock, bool& InvalidFound, ConnctTrac& connctTrac)
{
    AssrtLockHld(cs_main);
    i (m_mmpool) AssrtLockHld(m_mmpool->cs);
    const CBlockIndx* pindxOldTip = m_chain.Tip();
    const CBlockIndx* pindxFork = m_chain.FindFork(pindxMostWork);
    
    bool BlocksDisconnctd = als;