Scroll position snaps when adding content into section with autoScrolling: false

### Description
I'm using fullpage with the autoScrolling option disabled and want to append content to a section upon pressing a button. The section has the class `fp-auto-height` and contains a div into which the content is appended. When pressing the button and after `fullpage_api.reBuild();`, the scroll position snaps to the bottom of the current section or to the top of the next section.

### Link to isolated reproduction with no external CSS / JS
https://jsfiddle.net/mathiasritter/n4fxh96z/