### 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

int nProtLevel = PROTECTION_LEVEL_UNRESTRICTED;
        setsockopt(hListenSocket, IPPROTO_IPV6, IPV6_PROTECTION_LEVEL, (const char*)&nProtLevel, sizeof(int));
#endif
    }
    if (::bind(hListenSocket, (struct sockaddr*)&sockaddr, len) == SOCKET_ERROR)
    {
        int nErr = WSAGetLastError();
        if (nErr == WSAEADDRINUSE)
            strError = strprintf(_("Unable to bind to %s on this computer. %s is probably already running."), addrBind.ToString(), _(PACKAGE_NAME));
        else
            strError = strprintf(_("Unable to bind to %s on this computer (bind returned error %s)"), addrBind.ToString(), NetworkErrorString(nErr));
        LogPrintf("%s\n", strError);
        CloseSocket(hListenSocket);
        return false;
    }
    LogPrintf("Bound to %s\n", addrBind.ToString());
    
    if (listen(hListenSocket, SOMAXCONN) == SOCKET_ERROR)
    {
        strError = strprintf(_("Error: Listening for incoming connections failed (listen returned error %s)"), NetworkErrorString(WSAGetLastError()));
        LogPrintf("%s\n", strError);
        CloseSocket(hListenSocket);
        return false;
    }
    vhListenSocket.push_back(ListenSocket(hListenSocket, fWhitelisted));
    if (addrBind.IsRoutable() && fDiscover && !fWhitelisted)
        AddLocal(addrBind, LOCAL_BIND);
    return true;
}
void Discover(boost::thread_group& threadGroup)