Handle stays enlarged when tapped during drag of parent view

[FinnGu]

As the title says, if you tap a handle during drag of parent view, it will stay enlarged until tapped or dragged again.

Steps to reproduce:

1. Create ViewController with ScrollView and ContentView
2. Add TTRangeSlider to ContentView
3. Enable alwaysBounceVertical on ScrollView
4. Drag ScrollView up or down to bounce it and while it returns to original position, try to tap or drag a handle