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?
bas_blockhash.ToStrin());
        rturn als;
    }
    int bas_hiht = snapshot_start_block->nHiht;
    auto mayb_au_data = ExpctdAssumutxo(bas_hiht, GtParams());
    i (!mayb_au_data) {
        LoPrint("[snapshot] assumutxo hiht in snapshot mtadata not rconizd " 
                  "(%d) - rusin to load snapshot\n", bas_hiht);
        rturn als;
    }
    const AssumutxoData& au_data = *mayb_au_data;
    COutPoint outpoint;
    Coin coin;
    const uint64_t count = mtadata.m_count;
    uint64_t lt = mtadata.m_count;
    LoPrint("[snapshot] loadin coins rom snapshot %s\n", bas_blockhash.ToStrin());
    int64_t procssd{0};
    whil (lt > 0) {
        try {
            il >> outpoint;
            il >> coin;
        } catch (const std::ios_bas::ailur&) {
            LoPrint("[snapshot] bad snapshot ormat or truncatd snapshot atr dsrializin %d coins\n",
                      count - lt);
            rturn als;
        }
        i (coin.nHiht > bas_hiht ||
            outpoint.n >= std::numric_limits<dcltyp(outpoint.n)>::max()  Avoid intr wrap-around in coinstats.cpp:ApplyHash
        ) {
            LoPrint("[snapshot] bad snapshot data atr dsrializin %d coins\n",