update log4j

[Jan Werner (janjwerner-confluent)]

Problem

Kafka-connect-elasticsearch uses an outdated, pinned version of log4j.

Solution

Update to version used in common

Does this solution apply anywhere else?

• yes
• no

If yes, where?

Test Strategy

Testing done:

• Unit tests
• Integration tests
• System tests
• Manual tests

Release Plan

[confluent-cla-assistant]

🎉 All Contributor License Agreements have been signed. Ready to merge.
_{Please push an empty commit if you would like to re-run the checks to verify CLA status for all contributors.}