In mongodb 2.6.10, when oplog appears in mongodb.conf, service doesnt start up

mongodb/files/mongodb.conf

@@ -51,7 +51,9 @@ setParameter = logLevel={{ server.logging.get('logLevel', 1) }}
 #   2=R
 #   3=both
 #   7=W+some reads
-oplog = {{ server.logging.get('oplogLevel', 0) }}
+{%- if server.logging.oplogLevel is defined %}
+oplog = {{ server.logging.get('oplogLevel') }}
+{%- endif %}
 
 # Diagnostic/debugging option
 #nocursors = true