allow to give away some thrust for yaw control

src/modules/systemlib/mixer/mixer_multirotor.cpp

@@ -312,6 +312,9 @@ MultirotorMixer::mix(float *outputs, unsigned space, uint16_t *status_reg)
 			}
 		}
 		else if(out > 1.0f) {
+			// allow to reduce thrust to get some yaw response
+			float thrust_reduction = fminf(0.15f, out - 1.0f);
+			thrust -= thrust_reduction;
 			yaw = (1.0f - ((roll * _rotors[i].roll_scale + pitch * _rotors[i].pitch_scale) *
 				roll_pitch_scale + thrust + boost))/_rotors[i].yaw_scale;
 			if(status_reg != NULL) {