WD: spin box values are not commit when Property widget lose focus

1. Open WD, set the SeqPos element to the scene.
2. Set the "Region width" value to 300.
3a. Click to the free space on the scene.
Expected state: property editor loose focus, new value is applied.
3b. Or to the free space on the property editor (under all properties).
Expected state: "Region width" property loose focus, new value is applied.