Fix: set state to nil when patch building view loses focus

This is also what we do in the staging controller, and it makes it so that when
you exit the patch building view and then enter it again (for another file, or
the same one) we select the first hunk again.

pkg/gui/controllers/patch_building_controller.go

@@ -73,6 +73,8 @@ func (self *PatchBuildingController) GetOnFocus() func(types.OnFocusOpts) {
 
 func (self *PatchBuildingController) GetOnFocusLost() func(types.OnFocusLostOpts) {
 	return func(opts types.OnFocusLostOpts) {
+		self.context().SetState(nil)
+
 		self.c.Views().PatchBuilding.Wrap = true
 
 		if self.c.Git().Patch.PatchBuilder.IsEmpty() {