From what I can tell `CClientUIInterface::[signal_name]_disconnect` is a no-op.

In other words calling it does *not* disconnect the slot:

For example `uiInterface.NotifyBlockTip_disconnect(BlockNotifyGenesisWait);` in `AppInitMain(...)` does not disconnect `BlockNotifyGenesisWait` as one would expect. The result being that `BlockNotifyGenesisWait` is invoked for every new block :-)

Running `bitcoind` with some debug printing added shows the issue:

```
[signals] CClientUIInterface::ThreadSafeMessageBox_connect(...) entered with 0 connected slots.
[signals] CClientUIInterface::ThreadSafeMessageBox_connect(...) exited with 1 connected slots.
[signals] CClientUIInterface::ThreadSafeQuestion_connect(...) entered with 0 connected slots.
[signals] CClientUIInterface::ThreadSafeQuestion_connect(...) exited with 1 connected slots.
[signals] CClientUIInterface::InitMessage_connect(...) entered with 0 connected slots.
[signals] CClientUIInterface::InitMessage_connect(...) exited with 1 connected slots.
[signals] CClientUIInterface::InitMessage_connect(...) entered with 1 connected slots.
[signals] CClientUIInterface::InitMessage_connect(...) exited with 2 connected slots.
[signals] Calling uiInterface.NotifyBlockTip_connect(&RPCNotifyBlockChange) in OnRPCStarted()
[signals] CClientUIInterface::NotifyBlockTip_connect(...) entered with 0 connected slots.
[signals] CClientUIInterface::NotifyBlockTip_connect(...) exited with 1 connected slots.
[signals] Calling uiInterface.NotifyBlockTip_connect(BlockNotifyGenesisWait) in AppInitMain(...)
[signals] CClientUIInterface::NotifyBlockTip_connect(...) entered with 1 connected slots.
[signals] CClientUIInterface::NotifyBlockTip_connect(...) exited with 2 connected slots.
[signals] RPCNotifyBlockChange(...) was invoked.
[signals] BlockNotifyGenesisWait(...) was invoked.
[signals] Calling uiInterface.NotifyBlockTip_disconnect(BlockNotifyGenesisWait) in AppInitMain(...)
[signals] CClientUIInterface::NotifyBlockTip_disconnect(...) entered with 2 connected slots.
[signals] CClientUIInterface::NotifyBlockTip_disconnect(...) exited with 2 connected slots.
[signals] RPCNotifyBlockChange(...) was invoked.
[signals] BlockNotifyGenesisWait(...) was invoked.
[signals] RPCNotifyBlockChange(...) was invoked.
[signals] BlockNotifyGenesisWait(...) was invoked.
[signals] RPCNotifyBlockChange(...) was invoked.
[signals] BlockNotifyGenesisWait(...) was invoked.
... and so on ...
```

Note how `BlockNotifyGenesisWait(...)` is called also after `uiInterface.NotifyBlockTip_disconnect(BlockNotifyGenesisWait)`.

I think the problem is that the `disconnect(...)` member function of `boost::signals2::signal` expects a function pointer to be passed in (the same that was passed to `.connect(...)`), but we're doing:

```
void CClientUIInterface::signal_name##_disconnect(std::function<signal_name##Sig> fn)
{
    return g_ui_signals.signal_name.disconnect(&fn);
}
```
for (const auto& client : interfaces.chain_clients) {
        if (!client->verify()) {
            return false;
        }
    }
    
    
    
    
    
    assert(!g_banman);
    g_banman = MakeUnique<BanMan>(GetDataDir() / "banlist.dat", &uiInterface, gArgs.GetArg("-bantime", DEFAULT_MISBEHAVING_BANTIME));
    assert(!g_connman);
    g_connman = std::unique_ptr<CConnman>(new CConnman(GetRand(std::numeric_limits<uint64_t>::max()), GetRand(std::numeric_limits<uint64_t>::max())));
    peerLogic.reset(new PeerLogicValidation(g_connman.get(), g_banman.get(), scheduler, gArgs.GetBoolArg("-enablebip61", DEFAULT_ENABLE_BIP61)));
    RegisterValidationInterface(peerLogic.get());
    
    std::vector<std::string> uacomments;
    for (const std::string& cmt : gArgs.GetArgs("-uacomment")) {
        if (cmt != SanitizeString(cmt, SAFE_CHARS_UA_COMMENT))
            return InitError(strprintf(_("User Agent comment (%s) contains unsafe characters."), cmt));
        uacomments.push_back(cmt);
    }
    strSubVersion = FormatSubVersion(CLIENT_NAME, CLIENT_VERSION, uacomments);
    if (strSubVersion.size() > MAX_SUBVERSION_LENGTH) {
        return InitError(strprintf(_("Total length of network version string (%i) exceeds maximum length (%i). Reduce the number or size of uacomments."),
            strSubVersion.size(), MAX_SUBVERSION_LENGTH));
    }
    if (gArgs.IsArgSet("-onlynet")) {
        std::set<enum Network> nets;