### Peer is still banned, allthough ban endtime has been reached

Here the log line of the banned peer:

`2017-11-04 16:12:03 Misbehaving: 212.203.47.xxx:61681 peer=56085 (0 -> 100) BAN THRESHOLD EXCEEDED`

In the debug connection window, the peer shows up as banned, with the ban endtime of 2017-11-05 17:12:03 CET, see screenshot (marked blue peer).

Then today, 2017-11-05 around 10 o clock CET, I stopped bitcoind 0.15.0.1, replaced the binaries with 0.15.1rc1 and started bitcoind again.

Now, as the time of the screenshot is 17:40 CET, the ban endtime had been reached, but the peer does still show up as banned.

Edit: Situation unchanged at 20:46 CET.

### Expected behaviour
Peer disappears from the "Banned peers" list, when ban endtime has been reached.

### Actual behaviour
Peer does not disappear from the "Banned peers" list, allthough ban endtime has been reached and exceeded.

### Screenshots.
![bildschirmfoto](https://user-images.githubusercontent.com/8447873/32416947-f2e0129a-c251-11e7-9c92-528f0ff3ae5d.png)

### What version of bitcoin-core are you using?
0.15.0.1 / 0.15.1rc1

### Machine specs:
Linux amd64

{
    if (mapAskFor.size() > MAPASKFOR_MAX_SZ || setAskFor.size() > SETASKFOR_MAX_SZ)
        return;
    
    if (!setAskFor.insert(inv.hash).second)
        return;
    
    
    int64_t nRequestTime;
    limitedmap<uint256, int64_t>::const_iterator it = mapAlreadyAskedFor.find(inv.hash);
    if (it != mapAlreadyAskedFor.end())
        nRequestTime = it->second;
    else
        nRequestTime = 0;
    LogPrint(BCLog::NET, "askfor %s  %d (%s) peer=%d\n", inv.ToString(), nRequestTime, DateTimeStrFormat("%H:%M:%S", nRequestTime/1000000), id);
    
    int64_t nNow = GetTimeMicros() - 1000000;
    static int64_t nLastTime;
    ++nLastTime;
    nNow = std::max(nNow, nLastTime);
    nLastTime = nNow;
    
    nRequestTime = std::max(nRequestTime + 2 * 60 * 1000000, nNow);
    if (it != mapAlreadyAskedFor.end())
        mapAlreadyAskedFor.update(it, nRequestTime);
    else
        mapAlreadyAskedFor.insert(std::make_pair(inv.hash, nRequestTime));
    mapAskFor.insert(std::make_pair(nRequestTime, inv));
}
bool CConnman::NodeFullyConnected(const CNode* pnode)