GCC 12

Hi,
there is a build error in `src/ServiceDiscovery/ServicesBackend.cpp` with GCC 12
we are using on mPMT Debian distribution.

It is possible to fix error changing line 1107:

```
if(!SendCommand("W_QUERY"," select now()", &resp, std::min(500L,time_left.count()))){
```

with

```
if(!SendCommand("W_QUERY"," select now()", &resp, std::min(500LL,time_left.count()))){
```

(500L -> 500LL)

Thanks