fix(listmailuser): Don't parse comments when reading config

[polarathene]

Description

The quota support method dovecot_quota_to_hr() was failing when provided comment lines. Fixed by stripping them from the config used as input for the while loop.

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Not sure how useful a test is for this? (we do have some tests that detect if other commands work without parsing failures though) Probably don't need a test for this as failure impact is UX only? This provides basis of consistent/improved config parsing to avoid issue in general going forward.

Resolved concern

I haven't looked over the difference for the shell syntax for passing the input data to the while loop, but it seems the 2nd commit syntax looks more appropriate? I'm just referencing usage elsewhere in the project, so happy for @georglauterbach or @casperklein to weigh in on what is suitable 👍

done <<< "$(_config_without_comments "${DATABASE}")"
# vs (latest commit):
done < <(_config_without_comments "${DATABASE}")

sed usage variants (for _config_without_comments()):

sed -n -r '/^\s*[^#[:space:]]/p' "${1}"
# vs (latest commit):
sed '/^[[:space:]]*#/d' "${1}"

# another usage in project is (not sure what the '|| true' is for):
grep -v "^\s*$\|^\s*\#" || true
# and another:
grep -vE '^(\s*$|#)'

EDIT: Whoops, noticed that the patterns aren't equivalent matching (empty line, white-space only, comments) 😅

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• If necessary I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[polarathene]

I need this PR and it's follow-up merged before I can continue #2615

I'm hoping another maintainer will have some time soon to spare, otherwise it's going to add friction to getting these PRs ready while I have time to spare 😅

[georglauterbach]

👍🏼