Qt-ts failed to support context

Qt-ts does not seem to handle context.
Dataset: qt-everywhere (qt-4.8.7)

Steps to reproduce
1. Push translations/qt.ts with maven plugin
mvn org.zanata:zanata-maven-plugin:4.0.0-SNAPSHOT:push "-DfileTypes=TS"
2. In WebUI, file translations/qt.ts
3. Search "Invalid URL"

Expected:
First "Invalid URL" should have message context FakeReply"
Second "Invalid URL" should have message context Phonon::MMF

Actual:
All "Invalid URL" did not have message context at all.