
**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/utils.py
"""
    FAB does not know how to handle columns with leading underscores because
    they are not supported by WTForm. This hack will remove the leading
    '_' from the key to lookup the column names.
    """
    def __init__(self, obj, session=None):
        super().__init__(obj, session=session)
        def clean_column_names():
            if self.list_properties:
                self.list_properties = {k.lstrip('_'): v for k, v in self.list_properties.items()}
            if self.list_columns:
                self.list_columns = {k.lstrip('_'): v for k, v in self.list_columns.items()}
        clean_column_names()
    def is_utcdatetime(self, col_name):
        """Check if the datetime is a UTC one."""
        from airflow.utils.sqlalchemy import UtcDateTime
        if col_name in self.list_columns:
            obj = self.list_columns[col_name].type
            return (
                isinstance(obj, UtcDateTime)
                or isinstance(obj, sqla.types.TypeDecorator)
                and isinstance(obj.impl, UtcDateTime)
            )
        return False
    filter_converter_class = UtcAwareFilterConverter
FieldConverter.conversion_table = (
    ('is_utcdatetime', DateTimeWithTimezoneField, AirflowDateTimePickerWidget),
) + FieldConverter.conversion_table