Fix a repo stem

Change-Id: I7bba351cc4d2bfa1ced994a4f75483c6aec12d66
diff --git a/cicd/pipelines/tasks/task_update_unstable.jenkins b/cicd/pipelines/tasks/task_update_unstable.jenkins
index 60c2535..4d9a263 100644
--- a/cicd/pipelines/tasks/task_update_unstable.jenkins
+++ b/cicd/pipelines/tasks/task_update_unstable.jenkins
@@ -44,7 +44,7 @@
                 sh "cp /etc/aptly.conf ~/.aptly.conf"
                 withEnv(['GNUPGHOME=/var/lib/aptly/.gnupg']) {
                     def debianMirrorSnapshotName = getLatestSnapshot('debian-buster')
-                    def coreSnapshotName = getLatestSnapshot('core-unstable')
+                    def coreSnapshotName = getLatestSnapshot('unstable-core')
                     def bspSnapshotName  = getLatestSnapshot('unstable-bsp-enterprise')
                     def date = new Date()
                     String stamp = date.format("yyyyMMdd-HHmmss")