Update .gitlab-ci.yml file

.gitlab-ci.yml

@@ -19,6 +19,10 @@
 stages:          # List of stages for jobs, and their order of execution
   - build
 
+variables:
+  GIT_SUBMODULE_STRATEGY: recursive
+  GIT_SUBMODULE_FORCE_HTTPS: "true"
+  
 build-job:       # This job runs in the build stage, which runs first.
   stage: build
   script: