**What happened:**

My password for external Postgres RDS contained '@123' at the end which got appended to the host of the DB due to some bug. One can notice in the logs, the DB_HOST has an unwanted 123@ in the front of it  DB_HOST=**123@**{{postgres_host}}. I removed '@' character from the password and it worked fine. 

I am using the latest image of apache/airflow and using the official helm chart.

```
kc logs airflow-run-airflow-migrations-xxx
BACKEND=postgresql
DB_HOST=123@{{postgres_host}}
DB_PORT=5432
....................
ERROR! Maximum number of retries (20) reached.

Last check result:
$ run_nc '123@{{postgres_host}}' '5432'
Traceback (most recent call last):
  File "<string>", line 1, in <module>
socket.gaierror: [Errno -2] Name or service not known
Can't parse  as an IP address
```

**Steps to reproduce:**
One can easily reproduce this by using a password that contains the '@' character in it.
```
data:
  metadataConnection:
    user: {{postgres_airflow_username}}
    pass: {{postgres_airflow_password}}
    protocol: postgresql  
    host: {{postgres_host}}
    port: 5432
    db: {{postgres_airflow_dbname}}
```

**Expected behavior:**
Migrations should run irrespective if the Postgres password contains an @ character or not.
chart/tests/test_metadata_connection_secret.py
values = {
            "data": {
                "metadataConnection": {
                    **self.non_chart_database_values,
                    "sslmode": "require",
                }
            }
        }
        connection = self._get_connection(values)
        assert "postgresql://someuser:somepass@somehost:7777/somedb?sslmode=require" == connection
    def test_should_support_non_postgres_db(self):
        values = {
            "data": {
                "metadataConnection": {
                    **self.non_chart_database_values,
                    "protocol": "mysql",
                }
            }
        }
        connection = self._get_connection(values)
        
        assert "mysql://someuser:somepass@somehost:7777/somedb" == connection