Make "Preferences" button in ibus-setup work

[Ma Hsiao-chun]

The "Preferences" button in ibus-setup is not usable for Pinyin and Bopomofo engine currently.
A screenshot is provided as ibus-setup.png

To fix this problem, we can backport a patch from upstream.
https://github.com/ibus/ibus-pinyin/commit/a8f1c432491eb5cd125a3b4babf86f5a70a71740.patch

ProblemType: Bug
DistroRelease: Ubuntu 13.04
Package: ibus-pinyin 1.4.0-1build1
ProcVersionSignature: Ubuntu 3.8.0-9.18-generic 3.8.1
Uname: Linux 3.8.0-9-generic x86_64
ApportVersion: 2.9-0ubuntu2
Architecture: amd64
Date: Thu Mar 7 21:40:00 2013
InstallationDate: Installed on 2013-03-04 (2 days ago)
InstallationMedia: Ubuntu 13.04 "Raring Ringtail" - Alpha amd64 (20130303)
MarkForUpload: True
SourcePackage: ibus-pinyin
UpgradeStatus: No upgrade log present (probably fresh install)