[chronojump] Fix force options seen on encoder session menu

[Xavier de Blas <xaviblas src gnome org>]

commit 4e15df0abece609434526c7bc908ea7695fadb49
Author: Xavier de Blas <xaviblas gmail com>
Date:   Sat Jan 20 02:54:41 2018 +0100

    Fix force options seen on encoder session menu

 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 3d8145e..95ef2f8 100644
--- a/src/gui/chronojump.cs
+++ b/src/gui/chronojump.cs
@@ -3255,6 +3255,9 @@ public partial class ChronoJumpWindow
                }
                last_menuitem_mode_defined = true;
 
+               //notebooks_change also does this, but it's not called on encoder modes
+               showHideForceSensorControls(m == Constants.Menuitem_modes.FORCESENSOR);
+
                chronopicRegisterUpdate(false);
 
                chronojumpWindowTestsNext();