* stable-5.9:
Prepare 5.9.1-SNAPSHOT builds
JGit v5.9.0.202009080501-r
[releng] Enable japicmp for the fragments added in 5.8.0
GitlinkMergeTest: fix boxing warnings
Remove unused API problem filters
Add missing since tag on BundleWriter#addObjectsAsIs
GPG: include signer's user ID in the signature
Change-Id: Iaa96f9228752540f446fc232a49f31a738fd8d30
Signed-off-by: Matthias Sohn <matthias.sohn@sap.com>