Update panko config file permissions

Change-Id: I00cfc2a73a49939fd15a509ccf95b0242614fb21
Related-Prod: PROD-20751
diff --git a/panko/server.sls b/panko/server.sls
index bddebe1..c3efa2c 100644
--- a/panko/server.sls
+++ b/panko/server.sls
@@ -16,6 +16,8 @@
   file.managed:
   - source: salt://panko/files/{{ server.version }}/panko.conf.{{ grains.os_family }}
   - template: jinja
+  - mode: 0640
+  - group: panko
   - require:
     - sls: panko._ssl.mysql
     - pkg: panko_server_packages
@@ -130,4 +132,4 @@
   - require:
     - sls: panko._ssl.mysql
 
-{%- endif %}
\ No newline at end of file
+{%- endif %}