fix syntax error

chrony/defaults.yaml

@@ -13,7 +13,7 @@ chrony:
   options: iburst
   logdir: /var/log/chrony
   keyfile: /etc/chrony.keys
-  driftfile: /var/lib/chrony/drift,
+  driftfile: /var/lib/chrony/drift
   otherparams: [ 'rtcsync',
                  'makestep 10 3',
                  'stratumweight 0',