.gitlab-ci.yml: use mirror from github

.gitlab-ci.yml

@@ -37,7 +37,8 @@ build:
     - apk add --no-cache --upgrade bash coreutils
     # fetch dockerfile
     - BRANCH_NAME=$(echo ${CI_COMMIT_TAG} | sed 's/\-/\+/') && echo ${BRANCH_NAME}
-    - git clone -b ${BRANCH_NAME} --depth=1 https://gitlab.com/gitlab-org/omnibus-gitlab.git
+    # mirror of https://gitlab.com/gitlab-org/omnibus-gitlab.git
+    - git clone -b ${BRANCH_NAME} --depth=1 https://github.com/gitlabhq/omnibus-gitlab.git
     - cd ./omnibus-gitlab/docker
     # write RELEASE
     - echo "PACKAGECLOUD_REPO=gitlab-ce" > RELEASE && echo "RELEASE_PACKAGE=gitlab-ce" >> RELEASE && echo "RELEASE_VERSION=${CI_COMMIT_TAG}"  >> RELEASE && echo "DOWNLOAD_URL=https://packages.gitlab.com/gitlab/gitlab-ce/packages/ubuntu/focal/gitlab-ce_${CI_COMMIT_TAG}_arm64.deb/download.deb" >> RELEASE