Reduce log spam of verbose tasks (#3806)

Added a loop_control label to a few tasks that flood our logs.

roles/etcd/tasks/gen_certs_script.yml

@@ -107,6 +107,8 @@
     - inventory_hostname in groups['etcd']
     - sync_certs|default(false)
     - inventory_hostname != groups['etcd'][0]
+  loop_control:
+    label: "{{ item.item }}"
 
 - set_fact:
     my_etcd_node_certs: ['ca.pem',