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);
}
```
if (gArgs.GetBoolArg("-peerbloomfilters", DEFAULT_PEERBLOOMFILTERS))
        nLocalServices = ServiceFlags(nLocalServices | NODE_BLOOM);
    if (gArgs.GetArg("-rpcserialversion", DEFAULT_RPC_SERIALIZE_VERSION) < 0)
        return InitError("rpcserialversion must be non-negative.");
    if (gArgs.GetArg("-rpcserialversion", DEFAULT_RPC_SERIALIZE_VERSION) > 1)
        return InitError("unknown rpcserialversion requested.");
    nMaxTipAge = gArgs.GetArg("-maxtipage", DEFAULT_MAX_TIP_AGE);
    fEnableReplacement = gArgs.GetBoolArg("-mempoolreplacement", DEFAULT_ENABLE_REPLACEMENT);
    if ((!fEnableReplacement) && gArgs.IsArgSet("-mempoolreplacement")) {
        
        std::string strReplacementModeList = gArgs.GetArg("-mempoolreplacement", "");  
        std::vector<std::string> vstrReplacementModes;
        boost::split(vstrReplacementModes, strReplacementModeList, boost::is_any_of(","));
        fEnableReplacement = (std::find(vstrReplacementModes.begin(), vstrReplacementModes.end(), "fee") != vstrReplacementModes.end());
    }
    return true;
}
static bool LockDataDirectory(bool probeOnly)
{
    
    fs::path datadir = GetDataDir();
    if (!DirIsWritable(datadir)) {
        return InitError(strprintf(_("Cannot write to data directory '%s'; check permissions."), datadir.string()));
    }
    if (!LockDirectory(datadir, ".lock", probeOnly)) {
        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running."), datadir.string(), _(PACKAGE_NAME)));
    }
    return true;
}
bool AppInitSanityChecks()