In silent mode, calendar's notification doesn't trigger.

Information:
phablet@ubuntu-phablet:~$ system-image-cli -i
current build number: 63
device name: krillin
channel: ubuntu-touch/rc/bq-aquaris.en
last update: 2016-09-05 14:09:38
version version: 63
version ubuntu: 20160903
version tag: OTA-13-rc
version device: 20160606-ab415b2
version custom: 20160831-991-38-18

Precondition:
Silent mode set ON.

Step:
1. Launch Calendar app and set a new enevt.
2. Set the Reminder "On event" and fill in others form.
3. Wait to the event time.

Actual result:
In silent mode, the calendar notification doesn't work. (No reminder shows)

Expect result:
The calendar reminder should work normal in silent mode.