Metadata API: Remove unreachable code

unrecognized_fields is always initialized

Signed-off-by: Jussi Kukkonen <jkukkonen@vmware.com>

Author: Jussi Kukkonen

tuf/api/metadata.py

@@ -1025,8 +1025,6 @@ def __init__(
 
     @property
     def custom(self) -> Any:
-        if self.unrecognized_fields is None:
-            return None
         return self.unrecognized_fields.get("custom", None)
 
     @classmethod