Fix KeyError in ComponentContext (#255)

Co-authored-by: Joel Payne <15524072+LilSpazJoekp@users.noreply.github.com>

Author: TanguyMorelle

discord_slash/context.py

@@ -321,7 +321,10 @@ def __init__(
             )
             self.component = self.origin_message.get_component(self.custom_id)
 
-        self.selected_options = _json["data"]["values"] if self.component_type == 3 else None
+        self.selected_options = None
+
+        if self.component_type == 3:
+            self.selected_options = _json["data"].get("values", [])
 
     async def defer(self, hidden: bool = False, edit_origin: bool = False):
         """