[modal] body padding not reset after modal closed

[mahpah]

I notice that at this line

ngx-bootstrap/src/modal/modal.directive.ts

Line 420 in a1a54df

document.body.style.paddingRight = this.originalBodyPadding;

document.body.style.paddingRight should accept a string but originalBodyPadding is number, so paddingRight will keep its value as is. And the padding continue to expand each time I open a modal.

In my case, this is so weird that this issue was not happen util today.