[chronojump] When finish is pressed, now cannot press finish again or cancel

[Xavier de Blas <xaviblas src gnome org>]

commit cb8c0fedfd9b6aea5e244882ccc4f23e91f40160
Author: Xavier de Blas <xaviblas gmail com>
Date:   Tue Jan 10 13:29:35 2017 +0100

    When finish is pressed, now cannot press finish again or cancel

 src/gui/chronojump.cs |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/gui/chronojump.cs b/src/gui/chronojump.cs
index 0316a00..d45fe6f 100644
--- a/src/gui/chronojump.cs
+++ b/src/gui/chronojump.cs
@@ -3577,6 +3577,9 @@ public partial class ChronoJumpWindow
 
        private void on_finish_clicked (object o, EventArgs args) 
        {
+               //to avoid doble finish or cancel while finishing
+               hideButtons();
+
                event_execute_ButtonFinish.Clicked -= new EventHandler(on_finish_clicked);
                currentEventExecute.Finish = true;