Visible cell scrollbars in presentation mode

[jtpio]

Description

With jupyterlab-slideshow==0.3.0, scrollbars are visible when opening the slideshow:

Reproduce

Open any notebook as a slideshow.

Expected behavior

No scrollbar.

Context

jupyterlab-slideshow==0.3.0.

[brichet]

Thanks @jtpio.
Looking into it, it seems to be related to this rule.

[brichet]

Fixed by #23