include git_ssh in git environment

playbooks/roles/edxapp/tasks/deploy.yml

@@ -36,6 +36,8 @@
 
 - name: git prune before checking out
   shell: cd {{ edxapp_code_dir }} && git remote prune origin
+  environment:
+    GIT_SSH: "{{ edxapp_git_ssh }}"
   sudo_user: "{{ edxapp_user }}"
   notify:
   - "restart edxapp"