🐛 SWU: Fix issue with check config persistence from plugins
🐛 SWU: Fix issue with check config persistence from plugins

If we want to be able to in-place overlay the effective config, we MUST
do a deepcopy of the default or we'll actually operate on the default,
effectively leading to any changes to plugin check configs to be cleaned
up from the config file.

Closes #3765
Closes #3767

foosel/OctoPrint,foosel/OctoPrint,foosel/OctoPrint,foosel/OctoPrint