### 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

struct IGDdatas data;
    int r;
    r = UPNP_GetValidIGD(devlist, &urls, &data, lanaddr, sizeof(lanaddr));
    if (r == 1)
    {
        if (fDiscover) {
            char externalIPAddress[40];
            r = UPNP_GetExternalIPAddress(urls.controlURL, data.first.servicetype, externalIPAddress);
            if(r != UPNPCOMMAND_SUCCESS)
                LogPrintf("UPnP: GetExternalIPAddress() returned %d\n", r);
            else
            {
                if(externalIPAddress[0])
                {
                    CNetAddr resolved;
                    if(LookupHost(externalIPAddress, resolved, false)) {
                        LogPrintf("UPnP: ExternalIPAddress = %s\n", resolved.ToString().c_str());
                        AddLocal(resolved, LOCAL_UPNP);
                    }
                }
                else
                    LogPrintf("UPnP: GetExternalIPAddress failed.\n");
            }
        }
        std::string strDesc = "Bitcoin " + FormatFullVersion();
        try {
            while (true) {
#ifndef UPNPDISCOVER_SUCCESS
                
                r = UPNP_AddPortMapping(urls.controlURL, data.first.servicetype,