do not skip folder deletion if BlacklistedError during propagation

do not skip folder deletion if BlacklistedError during propagation

in case some propgation actions ends up with a BlacklistedError, we
would skip the deletions of local folders (even though they have been
deleted from server)

let's not skip them but rather keep track of the error status and
properly report them

Signed-off-by: Matthieu Gallien <matthieu.gallien@nextcloud.com>