Hi,
Well, supposing that you don't have any other payment method with automatic notifications, the simplest is to change the translation override like this:
PAYMENT_NOTIFICATION_STATUS="Hello,<br/>A payment notification was received with the status %2$s."
The %2$s allows the system to skip the first variable since we removed the first %s from the translation string.
docs.joomla.org/Formatted_fields_in_lang..._translation_strings
Otherwise, I'm afrais you'll have to change the code in the payment plugin to provide something else than the name of the payment plugin for that variable.