**Apache Airflow version**:

master

**Kubernetes version (if you are using kubernetes)** (use `kubectl version`):

**Environment**: breeze

**What happened**:

This DAG
```python
from airflow import models
from airflow.operators.dummy_operator import DummyOperator
from airflow.utils.dates import days_ago

with models.DAG("test", start_date=days_ago(1), schedule_interval=None,) as dag:
    t1 = DummyOperator(task_id="t1")
    t2 = DummyOperator(task_id="t2")
    t1 >> t2
```

is rendering like that:

<img width="1374" alt="Screenshot 2020-08-27 at 19 59 41" src="https://user-images.githubusercontent.com/9528307/91478403-11d7fb00-e8a0-11ea-91d0-d7d578bcb5a2.png">

**What you expected to happen**:

I expect to see same relations as defined in DAG file

**How to reproduce it**:

Render the example DAG from above.


**Anything else we need to know**:

I'm surprised by this bug 👀 

airflow/www/views.py
try:
                return int(value)
            except ValueError:
                return default
        arg_current_page = request.args.get('page', '0')
        arg_search_query = request.args.get('search', None)
        arg_tags_filter = request.args.getlist('tags', None)
        arg_status_filter = request.args.get('status', None)
        if request.args.get('reset_tags') is not None:
            flask_session[FILTER_TAGS_COOKIE] = None
            arg_tags_filter = None
        else:
            cookie_val = flask_session.get(FILTER_TAGS_COOKIE)
            if arg_tags_filter:
                flask_session[FILTER_TAGS_COOKIE] = ','.join(arg_tags_filter)
            elif cookie_val:
                arg_tags_filter = cookie_val.split(',')
        if arg_status_filter is None:
            cookie_val = flask_session.get(FILTER_STATUS_COOKIE)
            if cookie_val:
                arg_status_filter = cookie_val
            else:
                arg_status_filter = 'active' if hide_paused_dags_by_default else 'all'
                flask_session[FILTER_STATUS_COOKIE] = arg_status_filter
        else:
            status = arg_status_filter.strip().lower()