Core/Misc: fix some clang 5 warnings

src/server/worldserver/Main.cpp

@@ -241,7 +241,7 @@ extern int main(int argc, char** argv)
     if (networkThreads <= 0)
     {
         TC_LOG_ERROR("server.worldserver", "Network.Threads must be greater than 0");
-        return false;
+        return 1;
     }
 
     sWorldSocketMgr.StartNetwork(_ioService, worldListener, worldPort, networkThreads);