Add getChildren overload

app/src/main/java/com/todoroo/astrid/service/TaskCompleter.java

@@ -37,7 +37,7 @@ public class TaskCompleter {
     long completionDate = completed ? now() : 0L;
     setComplete(singletonList(item), completionDate);
     setComplete(googleTaskDao.getChildTasks(item.getId()), completionDate);
-    List<Long> caldavChildren = caldavDao.getChildren(singletonList(item.getId()));
+    List<Long> caldavChildren = caldavDao.getChildren(item.getId());
     if (!caldavChildren.isEmpty()) {
       setComplete(taskDao.fetch(caldavChildren), completionDate);
     }

app/src/main/java/org/tasks/data/CaldavDao.java

@@ -117,6 +117,10 @@ public abstract class CaldavDao {
   @Query("UPDATE caldav_tasks SET cd_parent = IFNULL((SELECT cd_task FROM caldav_tasks AS p WHERE p.cd_remote_id = caldav_tasks.cd_remote_parent), cd_parent) WHERE cd_calendar = :calendar AND cd_remote_parent IS NOT NULL and cd_remote_parent != ''")
   public abstract void updateParents(String calendar);
 
+  public List<Long> getChildren(long id) {
+    return getChildren(Collections.singletonList(id));
+  }
+
   public List<Long> getChildren(List<Long> ids) {
     return atLeastLollipop()
         ? getChildrenRecursive(ids)