Add retry for pkgrepo.managed

  * Add simple retry for pkgrepo.managed add op.
  * key_id fetch operation may fail
    due unstable connection or unstable key_server
    processing.

Change-Id: Id85920f257654f13cce0d907e344302ae3b668c1
diff --git a/linux/system/repo.sls b/linux/system/repo.sls
index bd56b5a..73bb33d 100644
--- a/linux/system/repo.sls
+++ b/linux/system/repo.sls
@@ -152,6 +152,11 @@
     - file: purge_sources_list_d_repos
             {%- endif %}
           {%- endif %}
+  - retry:
+      attempts: 5
+      until: True
+      interval: 5
+      splay: 2
         {%- else %}
 linux_repo_{{ name }}:
   pkgrepo.absent: