[gegl] lua: fix video playback position scrubbing

[Øyvind "pippin" Kolås <ok src gnome org>]

commit 7cc237cf9012497f646a35a21419c43af0f4a831
Author: Øyvind Kolås <pippin gimp org>
Date:   Fri Mar 22 02:38:43 2019 +0100

    lua: fix video playback position scrubbing

 bin/lua/viewer.lua | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/bin/lua/viewer.lua b/bin/lua/viewer.lua
index 668a00fac..97799920e 100644
--- a/bin/lua/viewer.lua
+++ b/bin/lua/viewer.lua
@@ -303,7 +303,7 @@ if o.is_video ~= 0 then
   mrg:listen(Mrg.DRAG, function(event)
     source:set_property('frame',
        GObject.Value(GObject.Type.INT,
-        (event.x - width *.05) / (width * .95) * frames
+        (event.x - height *.15) / (width - height * .3) * frames
     ))
     event:stop_propagate()
   end)