tap to click on login page is not active (setting is on)

[Viet Le]

The tap to click function does not work on the login page even though the setting is enabled in the systems menu.

ProblemType: Bug
DistroRelease: elementary 0.4
Package: elementary-desktop 1.412+467~daily~ubuntu0.4.1 [origin: LP-PPA-elementary-os-daily]
ProcVersionSignature: Ubuntu 4.4.0-24.43-generic 4.4.10
Uname: Linux 4.4.0-24-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.1-0ubuntu2.1
Architecture: amd64
CrashDB: elementary_meta
CurrentDesktop: Pantheon
Date: Thu Jun 23 08:49:19 2016
EcryptfsInUse: Yes
InstallationDate: Installed on 2016-06-22 (1 days ago)
InstallationMedia: elementary OS 0.4 "Loki" - Daily amd64 (20160613)
ProcEnviron:
 LANGUAGE=en_US
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: elementary-meta
SuspiciousXErrors:

ThirdParty: True
UpgradeStatus: No upgrade log present (probably fresh install)