lexicographic_sort_schema drops deprecation reason from input fields

[kathychurch]

The sort_input_fields function is dropping arguments. It needs to include a **merge_kwargs call like the sort_fields function does.

The result is that calling lexicographic_sort_schema drops information from the schema, including the deprecation reason.

[Cito]

Did you check with the latest version? I remember something that sounds like that has been fixed in the latest 3.2 and 3. releases.