refactor(CI): reformat build command

  - docker login -u "$CI_REGISTRY_USER" -p "$CI_REGISTRY_PASSWORD" $CI_REGISTRY

  - source environment

  - docker pull "$CI_REGISTRY_IMAGE" || true

  - |

      docker build --ulimit nofile=9000 --cache-from "$CI_REGISTRY_IMAGE" --pull

  - >

      docker build

      --ulimit nofile=9000

      --cache-from "$CI_REGISTRY_IMAGE"

      --pull

      --build-arg "BASE=$BASE"

      --build-arg "LDAP_PLUGIN_URL=$LDAP_PLUGIN_URL"

      --build-arg login_text="${LOGIN_TEXT}"