message: Fix RPC/pruneblockchain returned prune height
diff: @@ -1061,7 +1061,12 @@ static UniValue pruneblockchain(const JSONRPCRequest& request)
  }
  PruneBlockFilesManual(height);
  - return uint64_t(height);
  + const CBlockIndex* block = ::ChainActive().Tip();
  + assert(block);
  + while (block->pprev && (block->pprev->nStatus & BLOCK_HAVE_DATA)) {
  + block = block->pprev;
  + }
  + return uint64_t(block->nHeight);
  }
  static UniValue gettxoutsetinfo(const JSONRPCRequest& request)
  