I posted more information about the change at Change in the contribution process.
@zosrothko Thank you for your contribution. When using the GitHub UI, you have to add Signed-off-by manually line to the commit message to indicate that you accept the terms of Developer Certificate of Origin. As @jjustinic mentioned the options now are to start over or do the steps documented in our contributing guide. Even for a change done via GitHub web interface, you should still be able to fix your commits in https://github.com/zosrothko/gradle/tree/patch-3.