Hardcode version number into Info.plist-jammr

The @SHORT_VERSION@ variable only expands to the x.y version number and
not the x.y.z version number in Apple's documentation.  I have filed a
bug with Qt:

https://bugreports.qt-project.org/browse/QTBUG-40860

In the meantime we can hardcode the full version number.

Signed-off-by: Stefan Hajnoczi <stefanha@gmail.com>