fixing some threadin issue at the Snooze reminder activity

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

@@ -13,12 +13,16 @@ class SnoozeReminderActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
 
         showPickSecondsDialogHelper(config.snoozeTime, true, cancelCallback = { dialogCancelled() }) {
+            Thread {
                 val eventId = intent.getLongExtra(EVENT_ID, 0L)
                 val event = eventsDB.getEventWithId(eventId)
                 config.snoozeTime = it / 60
                 rescheduleReminder(event, it / 60)
+                runOnUiThread {
                     finishActivity()
                 }
+            }.start()
+        }
     }
 
     private fun dialogCancelled() {