
**Apache Airflow version**:
2.0.1

**Environment**:

- **OS**: Linux Mint 19.2 
- **Kernel**: 5.5.0-050500-generic #202001262030 SMP Mon Jan 27 01:33:36 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

**What happened**:

Seems that pagination doesn't work. I filter DAGs by tags and get too many results to get them at one page. When I click second page I'm redirected to the first one (actually, it doesn't matter if I click second, last or any other - I'm always getting redirected to the first one).

**What you expected to happen**:

I expect to be redirected to the correct page when I click number on the bottom of the page.

**How to reproduce it**:
1. Create a lot of DAGs with the same tag
2. Filter by tag
3. Go to the next page in the pagination bar

**Implementation example**:



```
from airflow import DAG
from airflow.utils.dates import days_ago
for i in range(200):
    name = 'test_dag_' + str(i)
    dag = DAG(
        dag_id=name,
        schedule_interval=None,
        start_date=days_ago(2),
        tags=['example1'],
    )
    globals()[name] = dag
```

airflow/www/views.py
dag_orm = session.query(models.DagModel).filter(models.DagModel.dag_id == dag_id).first()
        if not dag_orm:
            flash(f"Cannot find dag {dag_id}")
            return redirect(origin)
        execution_date = timezone.utcnow()
        dr = DagRun.find(dag_id=dag_id, execution_date=execution_date, run_type=DagRunType.MANUAL)
        if dr:
            flash(f"This run_id {dr.run_id} already exists")  
            return redirect(origin)
        run_conf = {}
        if request_conf:
            try:
                run_conf = json.loads(request_conf)
            except json.decoder.JSONDecodeError:
                flash("Invalid JSON configuration", "error")
                return self.render_template(
                    'airflow/trigger.html', dag_id=dag_id, origin=origin, conf=request_conf
                )
        dag = current_app.dag_bag.get_dag(dag_id)
        dag.create_dagrun(
            run_type=DagRunType.MANUAL,
            execution_date=execution_date,
            state=State.RUNNING,
            conf=run_conf,
            external_trigger=True,
            dag_hash=current_app.dag_bag.dags_hash.get(dag_id),
        )
        flash(f"Triggered {dag_id}, it should start any moment now.")
        return redirect(origin)
    def _clear_dag_tis(