Copter: increased ESC auto-cal delay

ArduCopter/esc_calibration.pde

@@ -125,8 +125,8 @@ static void esc_calibration_auto()
         delay(10);
     }
 
-    // delay for 3 seconds
-    delay(3000);
+    // delay for 5 seconds
+    delay(5000);
 
     // reduce throttle to minimum
     motors.throttle_pass_through(g.rc_3.radio_min);