fix the problem that the pull down refresh function fails when scrolling to the bottom

[hangfgithub]

fix the problem that the pull down refresh function fails when scrolling to the bottom.

Because after scrolling to the end, actionTriggered is set to true, when the pull-down refreshes, onStart will be triggered. At this time, lastScrollTop is considered to have a value, so it is returned

[iamdarshshah]

Thanks for the detailed diagnosis. The v7.0.0 rewrite removed lastScrollTop entirely and replaced the scroll-position comparison approach with touch/mouse delta tracking for pull-to-refresh, so this specific code path no longer exists. Closing as superseded.

If you'd like to keep contributing, check out the open issues or file a new one if you find something worth fixing. Looking forward to more contributions from you, let's make this the best infinite scroll library out there!