TYPO fix

bilby/gw/detector/calibration.py

@@ -184,7 +184,7 @@ class CubicSpline(Recalibrate):
 
     @property
     def delta_log_spline_points(self):
-        if not hasattr(self, "__delta_log_spline_points"):
+        if not hasattr(self, "_delta_log_spline_points"):
             self._delta_log_spline_points = self._log_spline_points[1] - self._log_spline_points[0]
         return self._delta_log_spline_points