Select check box will delete the tasks directly without notification

[Evan Wang]

$ system-image-cli -i
current build number: 83
device name: krillin
channel: ubuntu-touch/rc-proposed/bq-aquaris.en
last update: 2015-08-03 03:47:33
version version: 83
version ubuntu: 20150803
version device: 20150716-fb60d96
version custom: 20150717-820-30-25-vivid

Steps to reproduce:
1.Launch Tasks app
2.Swipe up from bottom to create some tasks
3.Back to All Tasks view
4.Select one task by checking the check box on the left

Expected results:
A prompt confirmation should be necessary

Actual results:
The checked task will be deleted immediately without any notification