[chronojump] Do not try to draw encoder signal cairo if user don't want it

[Xavier de Blas <xaviblas src gnome org>]

commit 2e1bc017da4946924a19d3e20b926a25ef87ee2c
Author: Xavier de Blas <xaviblas gmail com>
Date:   Tue Mar 29 11:20:58 2022 +0200

    Do not try to draw encoder signal cairo if user don't want it

 src/gui/app1/encoder.cs | 3 +++
 1 file changed, 3 insertions(+)
---
diff --git a/src/gui/app1/encoder.cs b/src/gui/app1/encoder.cs
index d8c5cc76b..63df4247d 100644
--- a/src/gui/app1/encoder.cs
+++ b/src/gui/app1/encoder.cs
@@ -6063,6 +6063,9 @@ public partial class ChronoJumpWindow
        }
        private void updateEncoderCaptureSignalCairo (bool inertial, bool forceRedraw)
        {
+               if(preferences.encoderCaptureShowOnlyBars == null || ! 
preferences.encoderCaptureShowOnlyBars.ShowSignal)
+                       return;
+
                if(cairoGraphEncoderSignal == null)
                        cairoGraphEncoderSignal = new CairoGraphEncoderSignal (
                                encoder_capture_signal_drawingarea_cairo, "title");