Fix incorrect parsing of diff chunks starting with ++ or --
Conversation: https://gitlab.com/gitlab-org/gitaly/issues/222
Fixes gitlab-ce#34431
Edited by username-removed-506061
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Conversation: https://gitlab.com/gitlab-org/gitaly/issues/222
Fixes gitlab-ce#34431