fix up call to make_response

TES/tes/apiendpoints.py

@@ -555,6 +555,7 @@ class CreateTunnel(Resource):
         will be passed in the body
         """
         import logging
+        import json
         logger = logging.getLogger()
         try:
             data = request.get_json()
@@ -580,7 +581,7 @@ class CreateTunnel(Resource):
                        user=username, host=loginhost,
                        internalfirewall=firewall,
                        localbind=localbind, authtok=authtok)
-            response = make_response({'localport':port})
+            response = make_response(json.dumps({'localport':port}),200)
             response.mime_type = 'application/json'
             response.set_cookie('twsproxyauth', authtok)
             return response