Make realtime scheduling less aggressive

On the Wine side. Instead of always having it enabled and disabling it
when it could potentially hurt (i.e. when handling GUI related things),
we'll now only enable it when it's potentially beneficial. This way we
don't have to constantly switch scheduling policies on the GUI thread.

src/wine-host/individual-host.cpp

@@ -37,8 +37,6 @@ int __attribute__((visibility("default")))
 __cdecl
 #endif
     main(int argc, char* argv[]) {
-    set_realtime_priority(true);
-
     // We pass the plugin format, the name of the VST2 plugin .dll file or VST3
     // bundle to load, the base directory for the Unix domain socket endpoints
     // to connect to and the process ID of the process the native plugin is