QCMake: use loadRelaxed if available

Added in 5.14 and load() was deprecated at the same time.

Source/QtDialog/QCMake.cxx

@@ -340,7 +340,11 @@ void QCMake::interrupt()
 
 bool QCMake::interruptCallback()
 {
+#if QT_VERSION < QT_VERSION_CHECK(5, 14, 0)
   return this->InterruptFlag.load();
+#else
+  return this->InterruptFlag.loadRelaxed();
+#endif
 }
 
 void QCMake::progressCallback(const std::string& msg, float percent)