security(files): scrub connector credentials on deletion

src/govoplan_files/backend/storage/connector_profiles.py

@@ -80,6 +80,8 @@ class ConnectorProfile:
 
     @property
     def credentials_configured(self) -> bool:
+        if not self.enabled:
+            return False
         mode = self.credential_mode.casefold()
         if mode in {"", "none", "anonymous"}:
             return True