don't run gitinfos by default

roles/kubernetes/preinstall/defaults/main.yml

 ---
+run_gitinfos: false
+
 common_required_pkgs:
   - python-httplib2
   - openssl

roles/kubernetes/preinstall/tasks/main.yml

 ---
 - include: gitinfos.yml
+  when: run_gitinfos
 
 - name: gather os specific variables
   include_vars: "{{ item }}"