Make session rows half as big in height as pojects rows.

Change-Id: I8c24d4e939d2701c10444bb2c37921a095fe636b
Reviewed-on: http://codereview.qt.nokia.com/2523Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

share/qtcreator/welcomescreen/widgets/RecentSessions.qml

@@ -38,7 +38,7 @@ HeaderItemView {
     model: sessionList
 
     delegate: Rectangle {
-        height: 60
+        height: 30
         width: dataSection.width
 
         Rectangle {