Truncate frequencies used in calibration

For calibration, the log10(frequnecy_array) causes log warning messaged (due to taking the log of 0). To resolve this, and also to provide a slight speed up, this only calculates the values in the frequency mask

bilby/gw/calibration.py

@@ -100,7 +100,7 @@ class CubicSpline(Recalibrate):
         Parameters
         ----------
         frequency_array: array-like
-            The log-frequency values to calculate the calibration factor for.
+            The frequency values to calculate the calibration factor for.
         prefix: str
             Prefix for calibration parameter names
         params : dict