Fix URL buttons context processing

Author: artem30801

discord_slash/dpy_overrides.py

@@ -23,7 +23,7 @@ def get_component(self, custom_id: int) -> typing.Optional[dict]:
         """
         for row in self.components:
             for component in row["components"]:
-                if component["custom_id"] == custom_id:
+                if "custom_id" in component and component["custom_id"] == custom_id:
                     return component