make_on_surface() to leave humidity undefined to maintain ABI compati…

…bility with 1.0

src/novas.c

@@ -6956,9 +6956,9 @@ int make_observer_in_space(const double *sc_pos, const double *sc_vel, observer
  * the given parameters.
  *
  * Note, that because this is an original NOVAS C routine, it does not have an argument to set
- * a humidity value (e.g. for radio refraction). As such the call will set humidity to 0.0.
- * To set the humidity, set the output structure's field after calling this funcion. Its unit
- * is [%], and so the range is 0.0--100.0.
+ * a humidity value (e.g. for radio refraction). As such, the humidity value remains undefined
+ * after this call. To set the humidity, set the output structure's field after calling this
+ * funcion. Its unit is [%], and so the range is 0.0--100.0.
  *
  * @param latitude      [deg] Geodetic (ITRS) latitude in degrees; north positive.
  * @param longitude     [deg] Geodetic (ITRS) longitude in degrees; east positive.
@@ -6981,7 +6981,9 @@ int make_on_surface(double latitude, double longitude, double height, double tem
   loc->height = height;
   loc->temperature = temperature;
   loc->pressure = pressure;
-  loc->humidity = 0.0;
+
+  // FIXME starting v2.0 set humidity to 0.0
+  //loc->humidity = 0.0;
 
   return 0;
 }