Properly guard for DMs in interaction creation

Fix #6794

discord/interactions.py

@@ -117,6 +117,7 @@ class Interaction:
             self.user = None
 
         # TODO: there's a potential data loss here
+        if self.guild_id:
             guild = self.guild or Object(id=self.guild_id)
             try:
                 self.user = Member(state=self._state, guild=guild, data=data['member'])