gscreen -fix preference file errors
gscreen -fix preference file errors

If the preference file was empty gscreen would error.
This was because the default return values were returned
as (I think) strings instead of bool, int or floats

Signed-off-by: cmorley <663b38f0e776e9171484159033cf8a402a4c1654@hotmail.com>

bobvanderlinden/machinekit,kinsamanka/machinekit,cdsteinkuehler/linuxcnc,EqAfrica/machinekit,cdsteinkuehler/linuxcnc,bobvanderlinden/machinekit,Cid427/machinekit,ArcEye/machinekit-testing,ikcalB/linuxcnc-mirror,strahlex/machinekit,ikcalB/linuxcnc-mirror,ianmcmahon/linuxcnc-mirror,unseenlaser/machinekit,kinsamanka/machinekit,bobvanderlinden/machinekit,ArcEye/machinekit-testing,aschiffler/linuxcnc,RunningLight/machinekit,strahlex/machinekit,bmwiedemann/linuxcnc-mirror,cdsteinkuehler/linuxcnc,araisrobo/machinekit,ArcEye/MK-Qt5,unseenlaser/linuxcnc,unseenlaser/machinekit,cnc-club/linuxcnc,Cid427/machinekit,Cid427/machinekit,ArcEye/MK-Qt5,narogon/linuxcnc,unseenlaser/linuxcnc,ArcEye/MK-Qt5,kinsamanka/machinekit,ArcEye/MK-Qt5,aschiffler/linuxcnc,araisrobo/machinekit,araisrobo/machinekit,cdsteinkuehler/MachineKit,RunningLight/machinekit,EqAfrica/machinekit,ikcalB/linuxcnc-mirror,araisrobo/linuxcnc,cnc-club/linuxcnc,cdsteinkuehler/linuxcnc,kinsamanka/machinekit,araisrobo/linuxcnc,cdsteinkuehler/linuxcnc,bobvanderlinden/machinekit,cdsteinkuehler/MachineKit,unseenlaser/linuxcnc,bobvanderlinden/machinekit,araisrobo/machinekit,bobvanderlinden/machinekit,cdsteinkuehler/MachineKit,ikcalB/linuxcnc-mirror,mhaberler/machinekit,unseenlaser/linuxcnc,araisrobo/linuxcnc,Cid427/machinekit,ianmcmahon/linuxcnc-mirror,strahlex/machinekit,araisrobo/machinekit,araisrobo/linuxcnc,kinsamanka/machinekit,cnc-club/linuxcnc,EqAfrica/machinekit,Cid427/machinekit,unseenlaser/linuxcnc,araisrobo/machinekit,unseenlaser/machinekit,unseenlaser/machinekit,kinsamanka/machinekit,ArcEye/MK-Qt5,unseenlaser/machinekit,bmwiedemann/linuxcnc-mirror,mhaberler/machinekit,strahlex/machinekit,narogon/linuxcnc,bmwiedemann/linuxcnc-mirror,ArcEye/machinekit-testing,cdsteinkuehler/MachineKit,bmwiedemann/linuxcnc-mirror,cnc-club/linuxcnc,bmwiedemann/linuxcnc-mirror,araisrobo/machinekit,bmwiedemann/linuxcnc-mirror,EqAfrica/machinekit,mhaberler/machinekit,EqAfrica/machinekit,ikcalB/linuxcnc-mirror,cdsteinkuehler/MachineKit,ikcalB/linuxcnc-mirror,cdsteinkuehler/linuxcnc,EqAfrica/machinekit,RunningLight/machinekit,strahlex/machinekit,mhaberler/machinekit,mhaberler/machinekit,ArcEye/MK-Qt5,bmwiedemann/linuxcnc-mirror,unseenlaser/machinekit,araisrobo/machinekit,ianmcmahon/linuxcnc-mirror,RunningLight/machinekit,aschiffler/linuxcnc,bobvanderlinden/machinekit,narogon/linuxcnc,Cid427/machinekit,mhaberler/machinekit,cnc-club/linuxcnc,RunningLight/machinekit,unseenlaser/machinekit,ianmcmahon/linuxcnc-mirror,kinsamanka/machinekit,RunningLight/machinekit,ArcEye/MK-Qt5,ArcEye/machinekit-testing,cnc-club/linuxcnc,ArcEye/MK-Qt5,mhaberler/machinekit,ArcEye/machinekit-testing,ArcEye/machinekit-testing,kinsamanka/machinekit,mhaberler/machinekit,unseenlaser/machinekit,Cid427/machinekit,EqAfrica/machinekit,ianmcmahon/linuxcnc-mirror,Cid427/machinekit,ArcEye/machinekit-testing,aschiffler/linuxcnc,RunningLight/machinekit,ianmcmahon/linuxcnc-mirror,strahlex/machinekit,ianmcmahon/linuxcnc-mirror,bobvanderlinden/machinekit,cdsteinkuehler/MachineKit,ikcalB/linuxcnc-mirror,narogon/linuxcnc,cnc-club/linuxcnc,aschiffler/linuxcnc,EqAfrica/machinekit,ArcEye/machinekit-testing,araisrobo/machinekit,narogon/linuxcnc,araisrobo/linuxcnc,strahlex/machinekit,RunningLight/machinekit