Make ScmService#pathForConfigFile behave like before (Fix #6646)

[abicky]

Is this a bugfix, or an enhancement? Please describe. This PR resolves https://github.com/rundeck/rundeck/issues/6646.

Describe the solution you've implemented As described on https://github.com/rundeck/rundeck/issues/6646#issuecomment-930416577, FrameworkService#getServerUUID used to return null if the cluster mode was disabled, that is, ScmService#pathForConfigFile used to return the same value "etc/scm-${integration}.properties" whether or not the cluster mode is enabled. So, I made the method ScmService#pathForConfigFile behave like before.

Describe alternatives you've considered none

Additional context This change is a breaking change for users who use Rundeck 3.3.4 or later with the cluster mode disabled and a fixed server UUID. The upgrade guide should mention it.

[dsiperek-vendavo]

Any updates on this issue that is blocking some from upgrading?

[stale[bot]]

In an effort to focus on bugs and issues that impact currently supported versions of Rundeck, we have elected to notify GitHub issue creators if their issue is classified as stale and close the issue. An issue is identified as stale when there have been no new comments, responses or other activity within the last 12 months. If a closed issue is still present please feel free to open a new Issue against the current version and we will review it. If you are an enterprise customer, please contact your Rundeck Support to assist in your request. Thank you, The Rundeck Team

[stale[bot]]

In an effort to focus on bugs and issues that impact currently supported versions of Rundeck, we have elected to notify GitHub issue creators if their issue is classified as stale and close the issue. An issue is identified as stale when there have been no new comments, responses or other activity within the last 12 months. If a closed issue is still present please feel free to open a new Issue against the current version and we will review it. If you are an enterprise customer, please contact your Rundeck Support to assist in your request. Thank you, The Rundeck Team

[abicky]

I rebased the branch on the main branch and confirmed it worked correctly.