tuned down Alt hold D gain

ArduCopter/Attitude.pde

@@ -187,7 +187,7 @@ get_nav_throttle(int32_t z_error)
 	output =  constrain((int)g.pi_throttle.get_p(rate_error), -160, 180);
 
 	// a positive climb rate means we're going up
-	rate_d =  ((rate_d + climb_rate)>>1) * 1; // replace with gain
+	rate_d =  ((rate_d + climb_rate)>>1) * .1; // replace with gain
 
 	// slight adjustment to alt hold output
 	output -= constrain(rate_d, -25, 25);