Removed duplicate property bind in Generic6DOFJoint.

Probably a copy paste error.

scene/3d/physics_joint.cpp

@@ -776,7 +776,6 @@ void Generic6DOFJoint::_bind_methods() {
 	ADD_PROPERTYI(PropertyInfo(Variant::REAL, "linear_motor_z/target_velocity"), "set_param_z", "get_param_z", PARAM_LINEAR_MOTOR_TARGET_VELOCITY);
 	ADD_PROPERTYI(PropertyInfo(Variant::REAL, "linear_motor_z/force_limit"), "set_param_z", "get_param_z", PARAM_LINEAR_MOTOR_FORCE_LIMIT);
 	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "linear_spring_z/enabled"), "set_flag_z", "get_flag_z", FLAG_ENABLE_LINEAR_SPRING);
-	ADD_PROPERTYI(PropertyInfo(Variant::BOOL, "linear_spring_z/enabled"), "set_flag_z", "get_flag_z", FLAG_ENABLE_LINEAR_SPRING);
 	ADD_PROPERTYI(PropertyInfo(Variant::REAL, "linear_spring_z/stiffness"), "set_param_z", "get_param_z", PARAM_LINEAR_SPRING_STIFFNESS);
 	ADD_PROPERTYI(PropertyInfo(Variant::REAL, "linear_spring_z/damping"), "set_param_z", "get_param_z", PARAM_LINEAR_SPRING_DAMPING);
 	ADD_PROPERTYI(PropertyInfo(Variant::REAL, "linear_spring_z/equilibrium_point"), "set_param_z", "get_param_z", PARAM_LINEAR_SPRING_EQUILIBRIUM_POINT);