stop caldav update listener if CalDAV sync is turned off

app/src/main/kotlin/com/simplemobiletools/calendar/pro/activities/MainActivity.kt

@@ -163,6 +163,7 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
         super.onDestroy()
         if (!isChangingConfigurations) {
             EventsDatabase.destroyInstance()
+            stopCalDAVUpdateListener()
         }
     }
 
@@ -290,6 +291,15 @@ class MainActivity : SimpleActivity(), RefreshRecyclerViewListener {
         }
     }
 
+    private fun stopCalDAVUpdateListener() {
+        if (isNougatPlus()) {
+            if (!config.caldavSync) {
+                val updateListener = CalDAVUpdateListener()
+                updateListener.cancelJob(applicationContext)
+            }
+        }
+    }
+
     @SuppressLint("NewApi")
     private fun checkShortcuts() {
         val appIconColor = config.appIconColor