Delete unused wheel base parameter

src/modules/rover_pos_control/RoverPositionControl.hpp

@@ -212,7 +212,6 @@ private:
 		(ParamFloat<px4::params::GND_THR_MAX>) _param_throttle_max,
 		(ParamFloat<px4::params::GND_THR_CRUISE>) _param_throttle_cruise,
 
-		(ParamFloat<px4::params::GND_WHEEL_BASE>) _param_wheel_base,
 		(ParamFloat<px4::params::GND_MAX_ANG>) _param_max_turn_angle,
 		(ParamFloat<px4::params::GND_ATT_P>) _param_att_p,
 		(ParamFloat<px4::params::GND_MAN_Y_MAX>) _param_gnd_man_y_max,

src/modules/rover_pos_control/rover_pos_control_params.c

@@ -48,19 +48,6 @@
  * Controller parameters, accessible via MAVLink
  */
 
-/**
- * Distance from front axle to rear axle
- *
- * A value of 0.31 is typical for 1/10 RC cars.
- *
- * @unit m
- * @min 0.0
- * @decimal 3
- * @increment 0.01
- * @group Rover Position Control
- */
-PARAM_DEFINE_FLOAT(GND_WHEEL_BASE, 0.31f);
-
 /**
  * L1 distance
  *