all: run goimports

gioui.org/ui was renamed from gioui.org/ui/ui before the release,
but the import order wasn't changed accordingly.

Signed-off-by: Elias Naur <mail@eliasnaur.com>

ui/widget/image.go

@@ -5,10 +5,10 @@ package widget
 import (
 	"image"
 
+	"gioui.org/ui"
 	"gioui.org/ui/draw"
 	"gioui.org/ui/f32"
 	"gioui.org/ui/layout"
-	"gioui.org/ui"
 )
 
 type Image struct {