fix: prevent crash in Chart.Render when repository has no commits (#2504)

Author: JC-Chung

src/Views/Chart.cs

@@ -54,7 +54,7 @@ public override void Render(DrawingContext context)
             base.Render(context);
 
             var samples = _samples;
-            if (samples == null || samples.Count == 0)
+            if (samples == null || samples.Count <= 0)
                 return;
 
             var w = Bounds.Width;