This error is harmless – an incorrect logging level. To remove these errors please turn off the the Automation for Jira feature in the General settings screen of the Git Integration for Jira plugin:
You can also install the fixed plugin version 4.3.0.1. It is private now as it is currently being tested, but you may download it from the Atlassian Marketplace and install manually:
https://marketplace-cdn.atlassian.com/files/616e6975-2499-4b65-bc51-e26a74e11f0e
