[xray]: Fixed the chart indentation issue that occurs when setting external RabbitMQ credentials

[grig777]

PR Checklist

• Chart Version bumped
• CHANGELOG.md updated
• Title of the PR starts with chart name (e.g. [artifactory])

What this PR does / why we need it:
The Helm chart templating, install or upgrade was failing when setting external credentials for RabbitMQ. The issue was caused by incorrect indentation in the generated YAML. An example configuration that previously broke templating:

rabbitmq:
  enabled: false
  external:
    url: '{{ include "xray.rabbitmq.extRabbitmq.url" . }}'
    secrets:
      username:
        name: xray-rabbitmq-creds
        key: username
      password:
        name: xray-rabbitmq-creds
        key: password
      url:
        name: xray-rabbitmq-creds
        key: url