Only write bastion ssh config when needed (#1810)

This will allow running Kubespray when the user who runs it doesn't
have write permissions to the Kubespray dir, at least when not using
bastion.

roles/bastion-ssh-config/tasks/main.yml

@@ -18,3 +18,4 @@
   template:
     src: ssh-bastion.conf
     dest: "{{ playbook_dir }}/ssh-bastion.conf"
+  when: has_bastion