correct name parsing in CI and snippet

examples/CI_code_snippets/5.ex_CI_build_image_and_upload_OSSR.md

@@ -48,7 +48,7 @@ build_docker_image:
     - docker push $CI_REGISTRY_IMAGE:$LAST_RELEASE
 
     # Save docker image into a file to be uploaded in next stage
-    - docker save -o Docker_$CI_PROJECT_NAME_$LAST_RELEASE.tar $CI_REGISTRY_IMAGE:$LAST_RELEASE
+    - docker save -o Docker_${CI_PROJECT_NAME}_$LAST_RELEASE.tar $CI_REGISTRY_IMAGE:$LAST_RELEASE
     - cd .. && mkdir -p build && cp Docker/*.tar build
     - ls build
   artifacts: