refactor: use C++11 default initializers

src/qt/rpcconsole.cpp

@@ -120,7 +120,7 @@ public:
         connect(&timer, &QTimer::timeout, [this]{ func(); });
         timer.start(millis);
     }
-    ~QtRPCTimerBase() {}
+    ~QtRPCTimerBase() = default;
 private:
     QTimer timer;
     std::function<void()> func;
@@ -129,7 +129,7 @@ private:
 class QtRPCTimerInterface: public RPCTimerInterface
 {
 public:
-    ~QtRPCTimerInterface() {}
+    ~QtRPCTimerInterface() = default;
     const char *Name() override { return "Qt"; }
     RPCTimerBase* NewTimer(std::function<void()>& func, int64_t millis) override
     {