better errorhandling, slimmed down optimizer

backend/src/main.py

@@ -30,7 +30,7 @@ def new_trip(preferences: Preferences, start: tuple[float, float], end: tuple[fl
     '''
     if preferences is None:
         raise HTTPException(status_code=406, detail="Preferences not provided")
-    if preferences.shopping.score == 0 and preferences.culture.score == 0 and preferences.nature.score == 0:
+    if preferences.shopping.score == 0 and preferences.sightseeing.score == 0 and preferences.nature.score == 0:
         raise HTTPException(status_code=406, detail="All preferences are 0.")
     if start is None:
         raise HTTPException(status_code=406, detail="Start coordinates not provided")