Hack to prevent warning for read-only wrapper in public links

Storage wrappers should normally always be registered inside a presetup
hook. However in the public link scenario this is not possible and
there is currently no good alternative with the current architecture.

Instead of logging a warning every time, this fix prevents the warning
to be shown but also adds a FIXME in the code for the future. This is
ok because this app is already using private/internal APIs at the
moment and should be reworked properly in the future.