Fix warning in DBusTubeChannel
Fix warning in DBusTubeChannel

Reviewed-by: Dario Freddi <a66a8e9b1cf6d2032724c37305b83cdda18c904e@kde.org>

tiagosh/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,freedesktop-unofficial-mirror/telepathy__telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,TelepathyIM/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,special/telepathy-qt-upstream,TelepathyQt/telepathy-qt,TelepathyIM/telepathy-qt,tiagosh/telepathy-qt,TelepathyIM/telepathy-qt,anantkamath/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,TelepathyQt/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,anantkamath/telepathy-qt,detrout/telepathy-qt,TelepathyIM/telepathy-qt,detrout/telepathy-qt,detrout/telepathy-qt,anantkamath/telepathy-qt,TelepathyIM/telepathy-qt,special/telepathy-qt-upstream,tiagosh/telepathy-qt,special/telepathy-qt-upstream,TelepathyQt/telepathy-qt,tiagosh/telepathy-qt,TelepathyQt/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt