Describe the bug
see description and discussion on #4493 (comment)

To Reproduce
Steps to reproduce the behavior:

1. have a smaller screen (width > than mobile view, height < than config dropdown height)
2. open config menu
3. cannot reach the last items of the dropdown height

Expected behavior
All items in the list are reachable

Environment information (please complete the following information):

• FreshRSS version: 1.19.2, 1.20.0-dev

Additional context
While 150% zoom is recommended in Windows on some (or all?) screens, we have to keep an eye on it.

Right now only Swage theme is affected, because the header is fixed. Other themes can be scrolled down.