Fix incorrect filename in swift-account-reaper ansible task

Change-Id: I36d8455e904732195edcd3862d4b4445346e1bc0
backport: liberty
Closes-Bug: #1504204

ansible/roles/swift/tasks/config.yml

@@ -110,7 +110,7 @@
 
 - name: Copying over swift-account-reaper JSON configuration file
   template:
-    src: "swift-account-reaper.j2"
+    src: "swift-account-reaper.json.j2"
     dest: "{{ node_config_directory }}/swift-account-reaper/config.json"
   when: inventory_hostname in groups['swift-account-server']