Migrate Preference.DeleteCategoryAndName to Sync by default (#10940)

app/post.go

@@ -766,8 +766,8 @@ func (a *App) DeletePost(postId, deleteByID string) (*model.Post, *model.AppErro
 }
 
 func (a *App) DeleteFlaggedPosts(postId string) {
-	if result := <-a.Srv.Store.Preference().DeleteCategoryAndName(model.PREFERENCE_CATEGORY_FLAGGED_POST, postId); result.Err != nil {
-		mlog.Warn(fmt.Sprintf("Unable to delete flagged post preference when deleting post, err=%v", result.Err))
+	if err := a.Srv.Store.Preference().DeleteCategoryAndName(model.PREFERENCE_CATEGORY_FLAGGED_POST, postId); err != nil {
+		mlog.Warn(fmt.Sprintf("Unable to delete flagged post preference when deleting post, err=%v", err))
 		return
 	}
 }