internal/gitlab: rename dupId to dupID
internal/gitlab: rename dupId to dupID

golint complains about some well-known acronyms like ID, so it requires
the use of ALL_CAPS for them.

Signed-off-by: Bruno Meneguele <82c7731bc2625bcbab88bc571aee6631ba3f66f3@redhat.com>

zaquestion/lab,zaquestion/lab