docs: update sample result on loki setup page

[qww1552]

What this PR does / why we need it:
Sample result in Install with Docker Compose is different from the actual result

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• Title matches the required conventional commits format, see here
  • Note that Promtail is considered to be feature complete, and future development for logs collection will be in Grafana Alloy. As such, feat PRs are unlikely to be accepted unless a case can be made for the feature actually being a bug fix to existing behavior.
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[CLAassistant]

All committers have signed the CLA.

[nicolevanderhoeven]

Hey @qww1552 , I saw that this is your first PR for Grafana! Just wanted to say thanks for spotting this and for contributing a fix. Appreciate you!

[JStickler]

[docs team] LGTM, thanks for taking the time to update the docs!