[commands] Fix broken handling of keyword only parameters.

Had a missing `param` argument in the new `do_conversion` code.

discord/ext/commands/core.py

@@ -413,7 +413,7 @@ class Command:
                 if self.rest_is_raw:
                     converter = self._get_converter(param)
                     argument = view.read_rest()
-                    kwargs[name] = await self.do_conversion(ctx, converter, argument)
+                    kwargs[name] = await self.do_conversion(ctx, converter, argument, param)
                 else:
                     kwargs[name] = await self.transform(ctx, param)
                 break