Fixes #23132: NPE when downloading customers

Reading that you see:

• It's a bugfix, not feature addition or such
• The actual ticket number in case you need to dig deeper.
• A quick blurb about what and where. The rest is in the code. If the issue title is good you often can simply re-use it (but not always).

It's plenty to orient yourself in case you need to dig in, plenty so that you can skip over the commit if you're looking for something else, and short enough to ignore. If you absolutely need to document more, do it under the fold but that headline there is what should show up in a list of commits.