[QA]: How to set SSL/TLS certificates when connecting to MySQL server as a replica?

This is what we do when connecting to MySQL server as a client:

```python
# https://github.com/PyMySQL/PyMySQL/issues/430#issuecomment-464837266
conn = pymysql.connect(
host='127.0.0.1',
port=3306,
user='repl',
password='123456',
ssl={
'ca': 'ssl/ca-cert.pem',
'cert': 'ssl/client-cert.pem',
'key': 'ssl/client-key.pem',
# Effectively equals to --ssl-mode=VERIFY_CA
'check_hostname': False,
}
)
```

Just wonder how to set SSL/TLS certificates when connecting to MySQL server as a replica?

Start by reviewing the replica connection path and the PyMySQL SSL options shown in the issue. Determine whether CA, client certificate, and key settings can be supplied when connecting as a replica; done means the supported configuration is documented or the limitation is clearly identified.

Written by the indexing model from the issue text.