Revert a default GIT_DEPTH for MR pipeline
What does this MR do?
Revert the DEFAULT_GIT_DEPTH_MERGE_REQUEST
value for git_depth
that was introduced in https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25504
Implementation idea from: https://gitlab.com/gitlab-org/gitlab-ce/issues/62418#note_176073801
Does this MR meet the acceptance criteria?
Conformity
Edited by Kamil Trzciński