[gnome-tetravex] Fix a typo.

[Arnaud B. <arnaudb src gnome org>]

commit cb2f947c405fa3eb1c8d03a3e654245f4d2635dd
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Wed Sep 18 03:24:00 2019 +0200

    Fix a typo.

 src/puzzle-view.vala | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/src/puzzle-view.vala b/src/puzzle-view.vala
index 3af0050..7df7f30 100644
--- a/src/puzzle-view.vala
+++ b/src/puzzle-view.vala
@@ -428,7 +428,7 @@ private class PuzzleView : Gtk.DrawingArea
 
         /* Select from the middle of the tile */
         x += size * 0.5 - selected_x_offset;
-        y += size * 0.5 - selected_x_offset;
+        y += size * 0.5 - selected_y_offset;
 
         int16 tile_y = (int16) Math.floor ((y - y_offset) / size);
         tile_y = tile_y.clamp (0, (int16) puzzle.size - 1);