V2.1.0使用tsdb遇到一个问题，假如tsdb刚好全部写满的时候重启了，再次开机 初始化tsdb的时候，会出现oldest sectors is 0x00000FFF, current using sector is 0xFFFFFFFF， 导致后续无法写入 about flashdb HOT 1 OPEN

/* search all sectors */
do {
    read_sector_info(db, sec_addr, sector, false);
    if (status == FDB_SECTOR_STORE_UNUSED || status == sector->status) {
        if (traversal) {
            read_sector_info(db, sec_addr, sector, true);
        }
        /* iterator is interrupted when callback return true */
        if (callback && callback(sector, arg1, arg2)) {
            return;
        }
    }
    traversed_len += db_sec_size(db);
} while ((sec_addr = get_next_sector_addr(db, sector, traversed_len)) != FAILED_ADDR);
// FDB_DEBUG("TSDB (%s) sec_addr is 0x%08" PRIX32 ", traversed_len is 0x%08" PRIX32 ".\n", db_name(db), sec_addr, traversed_len);  
if (sec_addr == FAILED_ADDR && traversed_len >= db_max_size(db) && sector->status == FDB_SECTOR_STORE_FULL) {
    
    FDB_DEBUG("TSDB (%s) all sectors are full and need to be reset \n\n", db_name(db));  
    db->cur_sec.addr = 0;
    format_sector(db, db->cur_sec.addr);
    read_sector_info(db, db->cur_sec.addr, &db->cur_sec, true);
    return;
}