[sr-dev] [kamailio/kamailio] db_mysql: built with mariadb-connector-c does not use TLS (Issue #3735)

### Description Applies to `db_mysql` built with mariadb-connector-c; TLS is not working

Option 1: configure mariadb server to use TLS (optional) Option 2: configure mariadb server to use TLS (mandatory)

### Troubleshooting 1. wireshark inspect the pcap dump of traffic to :3306 and look for ClientHello 2. gdb main kamailio process and set breakpoint at `SSL_new`

#### Reproduction 1. Option 1: server advertises SSL, but db_mysql will always choose plain 3. Option 2: server advertises SSL(and requires SSL), connection will fail

### Additional Information #### Kamailio version * master