Minor fix for i/o on failed lines

Author: JBorrow

velociraptor/autoplotter/metadata.py

@@ -72,8 +72,12 @@ def to_dict(self):
             additional_points_x_units=str(self.additional_x.units),
             additional_points_y=self.additional_y.value.tolist(),
             additional_points_y_units=str(self.additional_y.units),
-            bins_x=self.line.bins.value.tolist(),
-            bins_x_units=str(self.line.bins.units),
+            bins_x=self.line.bins.value.tolist()
+            if self.line.bins is not None
+            else None,
+            bins_x_units=str(
+                self.line.bins.units if self.line.bins is not None else None
+            ),
         )
 
         try: