[gnome-sudoku] Fix nullability of game and view objects

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 67a4efe04478736195e1a2b9adac7af515521899
Author: Michael Catanzaro <mcatanzaro gnome org>
Date:   Fri Nov 14 08:03:44 2014 -0600

    Fix nullability of game and view objects

 src/gnome-sudoku.vala |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)
---
diff --git a/src/gnome-sudoku.vala b/src/gnome-sudoku.vala
index 1ff9cb3..b1c73c9 100644
--- a/src/gnome-sudoku.vala
+++ b/src/gnome-sudoku.vala
@@ -34,9 +34,8 @@ public class Sudoku : Gtk.Application
 
     private ApplicationWindow window;
 
-    // The current game and view, if they exist
-    private SudokuGame game;
-    private SudokuView view;
+    private SudokuGame? game;
+    private SudokuView? view;
 
     private HeaderBar headerbar;
     private Stack main_stack;