gladevcp: hide error message from hal_lightbutton
gladevcp: hide error message from hal_lightbutton

error message from no HAL pin while using GLADE editor.

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