message: Avoid calling BanMan::SweepBanned() twice in a row
diff: @@ -43,16 +43,15 @@ void BanMan::DumpBanlist()
  static Mutex dump_mutex;
  LOCK(dump_mutex);
  + banmap_t banmap;
  {
  LOCK(m_cs_banned);
  SweepBanned();
  if (!BannedSetIsDirty()) return;
  + banmap = m_banned;
  }
  int64_t n_start = GetTimeMillis();
  -
  - banmap_t banmap;
  - GetBanned(banmap);
  if (m_ban_db.Write(banmap)) {
  SetBannedSetDirty(false);
  }
  