Update a content type in the query endpoint

Author: adamtheturtle

src/mock_vws/_query_validators/__init__.py

@@ -216,7 +216,7 @@ def validate_content_type_header(
 
     if pdict['boundary'].encode() not in request.body:
         context.status_code = codes.BAD_REQUEST
-        context.headers['Content-Type'] = 'text/html'
+        context.headers['Content-Type'] = 'text/html;charset=UTF-8'
         return (
             'java.lang.RuntimeException: RESTEASY007500: '
             'Could find no Content-Disposition header within part'

tests/mock_vws/test_query.py

@@ -271,7 +271,7 @@ def test_bogus_boundary(
         assert_vwq_failure(
             response=response,
             status_code=codes.BAD_REQUEST,
-            content_type='text/html',
+            content_type='text/html;charset=UTF-8',
         )
 
     def test_extra_section(