
**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
```

tests/www/test_utils.py
assert utils.should_hide_value_for_key("google_api_key")
    def test_sensitive_variable_should_be_hidden_ic(self):
        assert utils.should_hide_value_for_key("GOOGLE_API_KEY")
    @parameterized.expand(
        [
            ('key', 'TRELLO_KEY', True),
            ('key', 'TRELLO_API_KEY', True),
            ('key', 'GITHUB_APIKEY', True),
            ('key, token', 'TRELLO_TOKEN', True),
            ('mysecretword, mysensitivekey', 'GITHUB_mysecretword', True),
        ],
    )
    def test_sensitive_variable_fields_should_be_hidden(
        self, sensitive_variable_fields, key, expected_result
    ):
        with conf_vars({('admin', 'sensitive_variable_fields'): str(sensitive_variable_fields)}):
            assert expected_result == utils.should_hide_value_for_key(key)
    @parameterized.expand(
        [
            (None, 'TRELLO_API', False),
            ('token', 'TRELLO_KEY', False),
            ('token, mysecretword', 'TRELLO_KEY', False),
        ],
    )
    def test_normal_variable_fields_should_not_be_hidden(
        self, sensitive_variable_fields, key, expected_result
    ):
        with conf_vars({('admin', 'sensitive_variable_fields'): str(sensitive_variable_fields)}):
            assert expected_result == utils.should_hide_value_for_key(key)
    def check_generate_pages_html(self, current_page, total_pages, window=7, check_middle=False):