fix: only re-check pending payments

lnbits/core/services/payments.py

@@ -203,6 +203,7 @@ async def update_pending_payments(
     payments: list[Payment], delay: Optional[float] = None
 ) -> list[Payment]:
     for payment in payments:
+        if payment.pending:
             await update_pending_payment(payment)
         if delay is not None:
             await asyncio.sleep(delay)  # to avoid complete blocking