Split user create and ssh key generation

In order to allow an install and config split, but not
to have ssh keys left inside an pre-installed container,
the two tasks are split and tagged appropriately.

Change-Id: I33f4905363d102f65cda8769d1ff95bbce8f08f8

tasks/repo_post_install.yml

@@ -45,13 +45,22 @@
     system: "yes"
     createhome: "yes"
     home: "{{ repo_service_home_folder }}"
-    generate_ssh_key: "yes"
   tags:
     - pkg-repo-user
     - repo-key
     - repo-key-create
     - repo_server-install
 
+- name: Generate the nginx system user ssh key
+  user:
+    name: "{{ repo_service_user_name }}"
+    generate_ssh_key: "yes"
+  tags:
+    - pkg-repo-user
+    - repo-key
+    - repo-key-create
+    - repo_server-config
+
 - name: File and directory setup (non-root user)
   file:
     path: "{{ item.path }}"