[chronojump] CairoGraphRaceAnalyzer fixed crash on graph without data since recent commits (after 2.2.1)

[Xavier de Blas <xaviblas src gnome org>]

commit 261ad0f71302ed5fd5d0f90a4fbc8905436572f8
Author: Xavier de Blas <xaviblas gmail com>
Date:   Tue Mar 15 16:34:02 2022 +0100

    CairoGraphRaceAnalyzer fixed crash on graph without data since recent commits (after 2.2.1)

 src/gui/cairo/raceAnalyzer.cs | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)
---
diff --git a/src/gui/cairo/raceAnalyzer.cs b/src/gui/cairo/raceAnalyzer.cs
index b1458c595..710f9113d 100644
--- a/src/gui/cairo/raceAnalyzer.cs
+++ b/src/gui/cairo/raceAnalyzer.cs
@@ -90,9 +90,13 @@ public class CairoGraphRaceAnalyzer : CairoXY
                if(maxValuesChanged || forceRedraw || points_list.Count != points_list_painted)
                {
                        initGraph( font, 1, (maxValuesChanged || forceRedraw) );
-                       initGraphDone = true;
                        points_list_painted = 0;
                }
+               if(points_list == null || points_list.Count == 0)
+               {
+                       paintAxis();
+                       return;
+               }
 
                if(maxValuesChanged || forceRedraw)
                {