Fix thumbnail support in maemo5 engine
Fix thumbnail support in maemo5 engine

Due to the way in which avatar images are saved in maemo5,
have to convert the QImage into the correct format before
saving.

Also, don't scale the thumbnail image unnecessarily.

Relates to task QTMOBILITY-307

tmcguire/qt-mobility,KDE/android-qt-mobility,tmcguire/qt-mobility,qtproject/qt-mobility,KDE/android-qt-mobility,qtproject/qt-mobility,tmcguire/qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,KDE/android-qt-mobility,kaltsi/qt-mobility,qtproject/qt-mobility,qtproject/qt-mobility,qtproject/qt-mobility,enthought/qt-mobility,tmcguire/qt-mobility,tmcguire/qt-mobility,enthought/qt-mobility,enthought/qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,enthought/qt-mobility,KDE/android-qt-mobility,kaltsi/qt-mobility,enthought/qt-mobility,kaltsi/qt-mobility,kaltsi/qt-mobility