fix(TaskProcessingService): Use correct field name

[marcelklehr]

No description provided.

[marcelklehr]

/backport to stable30

[backportbot]

The backport to stable30 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable30
git pull origin stable30

# Create the new backport branch
git checkout -b backport/461/stable30

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick e41dbf9c

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/461/stable30

Error: Failed to cherry pick commits: error: no cherry-pick or revert in progress
fatal: cherry-pick failed

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Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.