Fix typo in project_properties.adoc

[grimsa]

Context

In this page: https://docs.gradle.org/current/userguide/project_properties.html there is a typo that throws formatting off:

Contributor Checklist

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• Make sure that all commits are signed off to indicate that you agree to the terms of Developer Certificate of Origin.
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• Provide integration tests (under <subproject>/src/integTest) to verify changes from a user perspective.
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• Update User Guide, DSL Reference, and Javadoc for public-facing changes.
• Ensure that tests pass sanity check: ./gradlew sanityCheck.
• Ensure that tests pass locally: ./gradlew <changed-subproject>:quickTest.

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• ❌ ❓must be fixed
• 🤔 💅 should be fixed
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[gitstream-cm]

📊 Changes by Platform: this PR is 50% new code

1 platform was affected

See details

Platform	Added Lines	% of Total Line Changes	Deleted Lines	% of Total Line Changes	Files Changed	% of Total Files Changed
documentation	1	50%	1	50%	1	100%

[lkasso]

Thank you for your contribution.