gladevcp -offset_widget: fix rare error of non-existant var file
gladevcp -offset_widget: fix rare error of non-existant var file

sometimes the var file is copied and deleted then re-saved by
 linuxcnc - account for that by ignoring the update.

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

ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror,ikcalB/linuxcnc-mirror