Pass lifetimebound reference to SingleThreadedSchedulerClient

src/validationinterface.cpp

@@ -40,7 +40,7 @@ public:
     // our own queue here :(
     SingleThreadedSchedulerClient m_schedulerClient;
 
-    explicit MainSignalsInstance(CScheduler *pscheduler) : m_schedulerClient(pscheduler) {}
+    explicit MainSignalsInstance(CScheduler& scheduler LIFETIMEBOUND) : m_schedulerClient(scheduler) {}
 
     void Register(std::shared_ptr<CValidationInterface> callbacks)
     {
@@ -92,7 +92,7 @@ static CMainSignals g_signals;
 void CMainSignals::RegisterBackgroundSignalScheduler(CScheduler& scheduler)
 {
     assert(!m_internals);
-    m_internals.reset(new MainSignalsInstance(&scheduler));
+    m_internals = std::make_unique<MainSignalsInstance>(scheduler);
 }
 
 void CMainSignals::UnregisterBackgroundSignalScheduler()