message: banlist (bugfix): allow CNode::SweepBanned() to run on interval
  allows CNode::SweepBanned() to run, even if !CNode::BannedSetIsDirty(),
  because if nBanUntil is over we want the ban to be disabled for these
  nodes
diff: @@ -1314,8 +1314,6 @@ void DumpAddresses()
  void DumpData()
  {
  DumpAddresses();
  -
  - if (CNode::BannedSetIsDirty())
  DumpBanlist();
  }
  @@ -2326,7 +2324,6 @@ bool CBanDB::Read(banmap_t& banSet)
  void DumpBanlist()
  {
  - int64_t nStart = GetTimeMillis();
  CNode::SweepBanned(); // clean unused entries (if bantime has expired)
  if (!CNode::BannedSetIsDirty())
  