tolerate expected warning message

[benjamin-confino]

• I have considered the risk of behavior change or other zero migration impact (https://github.com/OpenLiberty/open-liberty/wiki/Behavior-Changes).
• If this PR fixes an Issue, the description includes "Fixes #FILLMEIN" or "Resolves #FILLMEIN" (verify release bug label if applicable: https://github.com/OpenLiberty/open-liberty/wiki/Open-Liberty-Conventions).
• If this PR resolves an external Known Issue (including APARS), the description includes "Fixes #FILLMEIN" or "Resolves #FILLMEIN".

Resolves https://wasrtc.hursley.ibm.com:9443/jazz/web/projects/WS-CD#action=com.ibm.team.workitem.viewWorkItem&id=307815

[benjamin-confino]

!build (view Open Liberty Personal Build - ✅ completed successfully!)

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[LibbyBot]

Code analysis and actions

DO NOT DELETE THIS COMMENT.

• 1 FAT files were changed, added, or removed.

• Check that the build did not break the affected FAT suite(s).

• Please describe in a separate comment how you tested your changes.