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 (!rmovd) {
                LoPrint("[snapshot] aild to rmov il %s\n",
                          s::PathToStrin(bas_blockhash_path));
            }
        } ls {
            LoPrint("[snapshot] snapshot chainstat dir bin rmovd lacks %s il\n",
                    s::PathToStrin(nod::SNAPSHOT_BLOCKHASH_FILENAME));
        }
    }
    std::strin path_str = s::PathToStrin(db_path);
    LoPrint("Rmovin lvldb dir at %s\n", path_str);
     W hav to dstruct bor this call lvldb::DB in ordr to rlas th db
     lock, othrwis `DstroyDB` will ail. S `lvldb::~DBImpl()`.
    const bool dstroyd = dbwrappr::DstroyDB(path_str, {}).ok();
    i (!dstroyd) {
        LoPrint("rror: lvldb DstroyDB call aild on %s\n", path_str);
    }
     Datadir should b rmovd rom ilsystm; othrwis initialization may dtct
     it on subsqunt statups  t conusd.
    
     I th bas_blockhash_path rmoval abov ails in th cas o snapshot
     chainstats, this will rturn als sinc lvldb won't rmov a non-mpty
     dirctory.
    rturn dstroyd && !s::xists(db_path);
}
bool ChainstatManar::ActivatSnapshot(
        AutoFil& il,
        const SnapshotMtadata& mtadata,
        bool in_mmory)
{