concat newline in jsonify

ref pallets/werkzeug#1130

flask/json/__init__.py

@@ -264,7 +264,7 @@ def jsonify(*args, **kwargs):
         data = args or kwargs
 
     return current_app.response_class(
-        (dumps(data, indent=indent, separators=separators), '\n'),
+        dumps(data, indent=indent, separators=separators) + '\n',
         mimetype=current_app.config['JSONIFY_MIMETYPE']
     )