/apidocs.json in non-insecure mode returns invalid JSON

I start rudder like this:

$ docker run --mount type=bind,source=$HOME/.helm/repository/repositories.yaml,target=/root/.helm/repository/repositories.yaml,readonly -p 5000:5000 quay.io/acaleph/rudder
time="2018-09-25T19:36:13Z" level=info msg="Starting Rudder..." 
time="2018-09-25T19:36:13Z" level=info msg="CORS filter added." 
time="2018-09-25T19:36:13Z" level=info msg="OPTIONS filter added." 
time="2018-09-25T19:36:13Z" level=info msg="Auth filter added" 
time="2018-09-25T19:36:13Z" level=info msg="repo resource registered." 
time="2018-09-25T19:36:13Z" level=info msg="release resource registered." 
time="2018-09-25T19:36:13Z" level=info msg="[restful/swagger] listing is available at /apidocs.json" 
time="2018-09-25T19:36:13Z" level=info msg="[restful/swagger] /swagger/ is mapped to folder /opt/rudder/swagger" 
time="2018-09-25T19:36:13Z" level=info msg="Swagger enabled." 
time="2018-09-25T19:36:13Z" level=info msg="Rudder listening at: 0.0.0.0:5000"

On /apidocs.json rudder replies with invalid JSON (two documents in one):

$ http http://localhost:5000/apidocs.json
HTTP/1.1 200 OK
Content-Length: 642
Content-Type: application/json
Date: Tue, 25 Sep 2018 19:37:47 GMT

{
  "swaggerVersion": "1.2",
  "apis": [
   {
    "path": "/api/v1/repo",
    "description": "Helm repositories"
   },
   {
    "path": "/api/v1/releases",
    "description": "Helm releases"
   }
  ],
  "apiVersion": "dev",
  "info": {
   "title": "Rudder",
   "description": "RESTful proxy for the Tiller service"
  }
 }{
  "swaggerVersion": "1.2",
  "apis": [
   {
    "path": "/api/v1/repo",
    "description": "Helm repositories"
   },
   {
    "path": "/api/v1/releases",
    "description": "Helm releases"
   }
  ],
  "apiVersion": "dev",
  "info": {
   "title": "Rudder",
   "description": "RESTful proxy for the Tiller service"
  }
 }

When I pass --insecure to rudder, it replies with healthy JSON:

$ docker run --mount type=bind,source=$HOME/.helm/repository/repositories.yaml,target=/root/.helm/repository/repositories.yaml,readonly -p 5000:5000 quay.io/acaleph/rudder --insecure
time="2018-09-25T19:38:47Z" level=info msg="Starting Rudder..." 
time="2018-09-25T19:38:47Z" level=info msg="CORS filter added." 
time="2018-09-25T19:38:47Z" level=info msg="OPTIONS filter added." 
time="2018-09-25T19:38:47Z" level=info msg="repo resource registered." 
time="2018-09-25T19:38:47Z" level=info msg="release resource registered." 
time="2018-09-25T19:38:47Z" level=info msg="[restful/swagger] listing is available at /apidocs.json" 
time="2018-09-25T19:38:47Z" level=info msg="[restful/swagger] /swagger/ is mapped to folder /opt/rudder/swagger" 
time="2018-09-25T19:38:47Z" level=info msg="Swagger enabled." 
time="2018-09-25T19:38:47Z" level=info msg="Rudder listening at: 0.0.0.0:5000"

$ http http://localhost:5000/apidocs.json
HTTP/1.1 200 OK
Content-Length: 321
Content-Type: application/json
Date: Tue, 25 Sep 2018 19:39:16 GMT

{
    "apiVersion": "dev",
    "apis": [
        {
            "description": "Helm repositories",
            "path": "/api/v1/repo"
        },
        {
            "description": "Helm releases",
            "path": "/api/v1/releases"
        }
    ],
    "info": {
        "description": "RESTful proxy for the Tiller service",
        "title": "Rudder"
    },
    "swaggerVersion": "1.2"
}