Missing header rename

Author: bowenwr

openapi_python_client/templates/endpoint_macros.pyi

@@ -99,7 +99,7 @@ json_body: {{ endpoint.json_body.get_type_string() }},
 {{parameter.to_query_method_arg()}},
 {% endfor %}
 {% for parameter in endpoint.header_parameters %}
-{{ parameter.to_query_string() }},
+{{ parameter.to_query_method_arg() }},
 {% endfor %}
 {% endmacro %}