HADOOP-19719. Wildfly Followup: TestDelegatingSSLSocketFactory

[steveloughran]

Downgrade to a skipped tests if the OS doesn't have GLIBC_2.34.

For code changes:

• Does the title or this PR starts with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')?
• Object storage: have the integration tests been executed and the endpoint declared according to the connector-specific documentation?
• If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• If applicable, have you updated the LICENSE, LICENSE-binary, NOTICE-binary files?

[steveloughran]

the build seemed to fail in publishing, but the modified test wasn't executed, so we can't be sure it works again. I will have to rebase this after another change goes into trunk