Fix scheduling next notification

app/src/main/java/org/tasks/jobs/JobQueue.java

@@ -106,7 +106,8 @@ public class JobQueue {
     public synchronized boolean remove(List<? extends JobQueueEntry> entries) {
         boolean success = true;
         for (JobQueueEntry entry : entries) {
-            success &= jobs.remove(entry.getTime(), entry);
+            success &= !jobs.containsEntry(entry.getTime(), entry) ||
+                    jobs.remove(entry.getTime(), entry);
         }
         return success;
     }

app/src/main/java/org/tasks/notifications/NotificationManager.java

@@ -322,7 +322,7 @@ public class NotificationManager {
 
         // update last reminder time
         task.setReminderLast(new DateTime(when).endOfMinute().getMillis());
-        taskDao.saveExisting(task);
+        taskDao.save(task);
 
         NotificationCompat.Builder builder = new NotificationCompat.Builder(context, NotificationManager.NOTIFICATION_CHANNEL_DEFAULT)
                 .setCategory(NotificationCompat.CATEGORY_REMINDER)