fix typo in manage-container-images role

I had a var typo for the name used in this role. It was
container_cert_dir and it should be cert_dest_dir

Signed-off-by: Adam Miller <admiller@redhat.com>

roles/manage-container-images/tasks/main.yml

@@ -10,19 +10,19 @@
 
 - name: ensure cert dir exists
   file:
-    path: "{{container_dest_dir}}"
+    path: "{{cert_dest_dir}}"
     state: directory
 
 - name: install docker client cert for registry
   copy:
     src: "{{cert_src}}"
-    dest: "{{container_dest_dir}}/client.cert"
+    dest: "{{cert_dest_dir}}/client.cert"
     owner: root
     mode: 0600
 
 - name: install docker client key for registry
   copy:
     src: "{{key_src}}"
-    dest: "{{container_dest_dir}}/client.key"
+    dest: "{{cert_dest_dir}}/client.key"
     owner: root
     mode: 0600