connecting to mongo replicaset and using SSL as well

Hey Guys,

I am trying to connect to mongo_replset using SRV record but am unable to connect,

using below config.
```
@type mongo_replset
connection_string mongodb+srv://username:password@mongo-server-srv-example.com/log_db?tls=true&authSource=admin&replicaSet=mongo-rep
ssl true
ssl_ca_cert /tmp/tls
```
it does not work with this config, I am creating all this using code so don't have names of nodes behind the mongo replica set (hosted on DigitalOcean).

config works when I put node name in host entry like below. but this is not the best way in production.

```
@type mongo_replset
host mongo-server-node-example.com:27017
replica_set mongo-repl
database db
user user
password "password"
ssl true
ssl_ca_cert /tmp/tls
```

Please suggest. Thanks!