gate-quickstart: force repo checkout

We need to use force to be able to overwrite the current repo state as
the quickstart repo is already checked out during gating.

Change-Id: Ibb0eeca6a74efccdbd5c2eba84f9e96bab187ec3

roles/gate-quickstart/tasks/checkout.yml

@@ -8,6 +8,7 @@
     repo: 'https://{{ gated_change.host }}/{{ gated_change.project }}'
     dest: '{{ lookup("env", "WORKSPACE") }}/{{ gated_project_name }}'
     refspec: '{{ gated_change.refspec }}'
+    force: yes
     version: 'FETCH_HEAD'
   # do not check out the gated change if it was already cloned by the jenkins job
   when: gated_change.project != "{{ lookup('env', 'GERRIT_PROJECT') }}"