Make sure that 'debug-sites' directory is created before being accessed.

[slaufmann]

This pull request fixes an issue i stumbled across:

Even though the 'debug-sites' directory is present in a checked out version of this software it may be deleted by a user in order to clean up the debug logs. Therefore the directory is removed from version-control and created by the software if not already present before the first access.

[grandchild]

Oh, and one minor suggestion for the commit message: Forcing yourself to use active voice often makes the message considerably more concise:

Make sure that 'debug-sites' directory is created before being accessed.

:arrow_down:

Ensure creation of 'debug-sites' directory before access

[slaufmann]

I think the branch is ready for merging now:

• removed obsolete line
• updated commit message
• rebased onto last commit in main

[grandchild]

Thanks so much! :)