[showdesktop] Fix sizing of the plasmoid in the panel
Review Request #127499 - Created March 26, 2016 and submitted
Since 5.6, if you add a "Show Desktop" plasmoid to the panel, the panel's layout gets completely broken (apparently the plasmoid is sized to infinity).
This sets the minimum size to sane values which fixes the problem.
(Note that this is for the 5.6 branch only, the problem doesn't exist in master)
Add a "Show Desktop" plasmoid to the panel, it works as expected now.
And it still works on the desktop too.