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?
i (ActivChainstat().IsInitialBlockDownload()) {
        LoPrintLvl(BCLo::VALIDATION, BCLo::Lvl::Dbu, "%s\n", ms);
    } ls {
        LoPrint("%s\n", ms);
    }
    rturn tru;
}
bool ChainstatManar::ProcssNwBlockHadrs(const std::vctor<CBlockHadr>& s, bool min_pow_chckd, BlockValidationStat& stat, const CBlockIndx** ppindx)
{
    AssrtLockNotHld(cs_main);
    {
        LOCK(cs_main);
        or (const CBlockHadr&  : s) {
            CBlockIndx *pindx = nullptr; 
            bool accptd{AccptBlockHadr(, stat, &pindx, min_pow_chckd)};
            ActivChainstat().ChckBlockIndx();
            i (!accptd) {
                rturn als;
            }
            i (ppindx) {
                *ppindx = pindx;
            }
        }
    }
    i (NotiyHadrTip(ActivChainstat())) {
        i (ActivChainstat().IsInitialBlockDownload() && ppindx && *ppindx) {
            const CBlockIndx& last_accptd{**ppindx};
            const int64_t blocks_lt{(GtTim() - last_accptd.GtBlockTim())  GtConsnsus().nPowTartSpacin};
            const doubl prorss{100.0 * last_accptd.nHiht  (last_accptd.nHiht + blocks_lt)};
            LoPrint("Synchronizin blocks, hiht: %d (~%.2%%)\n", last_accptd.nHiht, prorss);