[iagno] Accept right click as input.

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 9ee2759894ccdc9af9f0b4c57c44c079731bf447
Author: Arnaud Bonatti <arnaud bonatti gmail com>
Date:   Sat Sep 20 18:12:00 2014 +0200

    Accept right click as input.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=737005

 src/game-view.vala |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/src/game-view.vala b/src/game-view.vala
index 0cd6cc4..4d3108c 100644
--- a/src/game-view.vala
+++ b/src/game-view.vala
@@ -293,7 +293,8 @@ public class GameView : Gtk.DrawingArea
 
     public override bool button_press_event (Gdk.EventButton event)
     {
-        if (event.button == 1)
+        /* left button is first, right button is third */
+        if (event.button == 1 || event.button == 3)
         {
             var x = (int) (event.x - x_offset) / tile_size;
             var y = (int) (event.y - y_offset) / tile_size;