Update SDK/installer qt src package url

Update the url where from to fetch qt sources for IFW builds.
The updated qt src package contains manually patched qmake.conf file
for win32-msvc2008. See:

https://qt.gitorious.org/installer-framework/installer-framework/


blobs/master/README

Change-Id: Id0fbee0a48f7a03c404bfd4b95ade1069f819a6e
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Reviewed-by: Tim Jenssen <tim.jenssen@nokia.com>