Fix build warning in _rangemedian.cpp
Fix build warning in _rangemedian.cpp

airspeed-velocity/asv,qwhelan/asv,qwhelan/asv,spacetelescope/asv,airspeed-velocity/asv,airspeed-velocity/asv,spacetelescope/asv,airspeed-velocity/asv,spacetelescope/asv,qwhelan/asv,qwhelan/asv,spacetelescope/asv