Revert "[maven-release-plugin] prepare release 6.2.0-ga1"

This reverts commit 6eddc2e6dceff8c89b62609f34f857a1f88c1d53.
Revert "Prepare 6.2.0-ga1 release."

This reverts commit 7da6e7b4a97a9407c1d933ba2780d67b66e58b24.