fix: Only fallback to airdate when Sonarr has no import date

- Modified fallback logic to only use airdate as dateadded when source is NOT 'sonarr:history.import'
- This prevents using airdate fallback when Sonarr has valid import dates available
- Ensures Sonarr import dates are prioritized over airdate fallbacks
- Addresses issue where episodes with valid Sonarr import dates were still falling back to airdates

VERSION

@@ -1 +1 @@
-2.0.8
+2.0.9