
**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
html_code = Markup(
                highlight(
                    code, lexers.PythonLexer(), HtmlFormatter(linenos=True)  
                )
            )
        except Exception as e:  
            all_errors += (
                "Exception encountered during "
                + f"dag_id retrieval/dag retrieval fallback/code highlighting:\n\n{e}\n"
            )
            html_code = Markup('<p>Failed to load file.</p><p>Details: {}</p>').format(  
                escape(all_errors)
            )
        return self.render_template(
            'airflow/dag_code.html',
            html_code=html_code,
            dag=dag_orm,
            title=dag_id,
            root=request.args.get('root'),
            wrapped=conf.getboolean('webserver', 'default_wrap'),
        )
    @expose('/dag_details')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_RUN),
        ]
    )
    @provide_session
    def dag_details(self, session=None):