Refactor to meet line length standard

[benjagooder]

Google coding standard for line length is 100 characters. This fix breaks one long line of 103 characters down into 3 smaller lines. No logic was changed.

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• Change in CHANGELOG.md described
• Tests created for changes
• Manually tested changed features in running JabRef
• Screenshots added in PR description (for bigger UI changes)
• Ensured that the git commit message is a good one
• Check documentation status (Issue created for outdated help page at help.jabref.org?)