Use Alarm::parentUid instead of the ETM specific custom property hack

Made possible and neccessary by akonadi-calendar!10.

kalendarac/kalendaralarmclient.cpp

@@ -5,6 +5,8 @@
 #include "alarmnotification.h"
 #include "notificationhandler.h"
 
+#include <akonadi-calendar_version.h>
+
 #include <KCheckableProxyModel>
 #include <KConfigGroup>
 #include <KLocalizedString>
@@ -172,7 +174,11 @@ void KalendarAlarmClient::checkAlarms()
 
     const Alarm::List alarms = mCalendar->alarms(from, mLastChecked, true /* exclude blocked alarms */);
     for (const Alarm::Ptr &alarm : alarms) {
+#if AKONADICALENDAR_VERSION < QT_VERSION_CHECK(5, 19, 41)
         const QString uid = alarm->customProperty("ETMCalendar", "parentUid");
+#else
+        const QString uid = alarm->parentUid();
+#endif
         const KCalendarCore::Incidence::Ptr incidence = mCalendar->incidence(uid);
         QString timeText;