iOS11 PageEnabled MJRefresh 偏移

UITableView 添加一下设置，关键是_tableView.estimatedRowHeight = 0;

if (@available(iOS 11.0, *)) {
        _tableView.estimatedRowHeight = 0;
        _tableView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
    } else {
        self.automaticallyAdjustsScrollViewInsets = NO;
    }

@weakify(self);
MJRefreshAutoNormalFooter *footer = [MJRefreshAutoNormalFooter footerWithRefreshingBlock:^{
        @strongify(self);
        self->_tableView.pagingEnabled = NO;
       dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(5 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
            [self->_tableView.mj_footer endRefreshing];
            self->_tableView.pagingEnabled = YES; //  耗时操作后设置
        });
    }];
footer.automaticallyChangeAlpha = YES;
footer.triggerAutomaticallyRefreshPercent = -10;
_tableView.mj_footer = footer;