AP_NavEKF: added rejecting_airspeed flag in EKF status

libraries/AP_NavEKF/AP_Nav_Common.h

@@ -38,6 +38,7 @@ union nav_filter_status {
         bool gps_glitching      : 1; // 14 - true if GPS glitching is affecting navigation accuracy
         bool gps_quality_good   : 1; // 15 - true if we can use GPS for navigation
         bool initalized         : 1; // 16 - true if the EKF has ever been healthy
+        bool rejecting_airspeed : 1; // 17 - true if we are rejecting airspeed data
     } flags;
     uint32_t value;
 };