ES host resolves to 9200 port even when protocol https is configured

**APM Server version** (`apm-server version`): `8.x`, `7.17`

**Description of the problem including expected versus actual behavior**:

When configuring ES output without specificially passing the port, APM Server adds port `9200`, instead of not adding any port or adding `443`.

**Steps to reproduce**:

1. Create Elastic Cloud deployment and copy & paste ES URL and ES secret to `apm-server.yml` configuration
2. Start APM Server and try to ingest data
3. Observe that connection to Elasticsearch times out.

If adding `:443` to the ES Url, a connection can succesfully be established.