fix(aurora): fixed a valueerror

aurora/models/moderation.py

@@ -166,7 +166,7 @@ class Moderation(AuroraGuildModel):
 
     @classmethod
     def from_result(cls, bot: Red, result: Iterable, guild_id: int) -> "Moderation":
-        if result[7] is not None:
+        if result[7] is not None and result[7] != "NULL":
             hours, minutes, seconds = map(int, result[7].split(':'))
             duration = timedelta(hours=hours, minutes=minutes, seconds=seconds)
         else: