[gnome-tetravex] Fix last commit.

[Arnaud B. <arnaudb src gnome org>]

commit 6fca569cec739bc920411c4cefd1cc9b176d137b
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Wed Sep 18 12:18:14 2019 +0200

    Fix last commit.
    
    When starting a new game, the
    last selected tile was drawn.

 src/puzzle-view.vala | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/src/puzzle-view.vala b/src/puzzle-view.vala
index fe8c417..a1696a8 100644
--- a/src/puzzle-view.vala
+++ b/src/puzzle-view.vala
@@ -55,6 +55,7 @@ private class PuzzleView : Gtk.DrawingArea
                 SignalHandler.disconnect_by_func ((!) _puzzle, null, this);
 
             _puzzle = value;
+            last_selected_tile = null;
             tiles.remove_all ();
             for (uint8 y = 0; y < ((!) _puzzle).size; y++)
             {