Merge conditionals and remove redundant check

Author: chillymosh

twitchio/ext/commands/core.py

@@ -387,15 +387,12 @@ async def _invoke(self, context: Context) -> None:
         context._invoked_with = f"{context._invoked_with} {trigger}"
         context._subcommand_trigger = trigger or None
 
-        if not trigger:
+        if not trigger or not next_ and self._invoke_fallback:
             await super()._invoke(context=context)
 
-        elif trigger and next_:
+        elif next_:
             await next_.invoke(context=context)
 
-        elif self._invoke_fallback:
-            await super()._invoke(context=context)
-
         else:
             raise CommandNotFound(f'The sub-command "{trigger}" for group "{self._name}" was not found.')