Fix invalid UI Status with disabledAutoPreview
* src/mapl.cpp: Invalidate UI when we return early from decryptVerify_o
When the disableAutoPreview option is set the
UI (icon/Status) is not upteded as we return
early from decryptVerify_o.
In this case we now invalidate the ui as a new
item was processed but we don't now its status yet.
- GnuPG-Bug-Id: T7803