buildinstaller.yml: fix format_sshkeys

tasks/buildinstaller.yml

@@ -25,7 +25,7 @@
 
 - name: install ssh public key
   copy:
-    src: "{{ '%s/ansible.pub' | format(ansible_certificates) }}"
+    src: "{{ '%s/ansible.pub' | format(ansible_sshkeys) }}"
     dest: "{{ '%s/opt/ansible.pub' | format(linux_build_installer_root) }}"
 
 - name: install basic installer scripts