Rover: only report system status after init has completed

This reduces errors reported to the GCS during startup

APMrover2/GCS_Mavlink.cpp

@@ -307,10 +307,14 @@ bool GCS_MAVLINK_Rover::try_send_message(enum ap_message id)
         return true;
 
     case MSG_EXTENDED_STATUS1:
-        CHECK_PAYLOAD_SIZE(SYS_STATUS);
+        // send extended status only once vehicle has been initialised
-        rover.send_extended_status1(chan);
+        // to avoid unnecessary errors being reported to user
-        CHECK_PAYLOAD_SIZE(POWER_STATUS);
+        if (initialised) {
-        send_power_status();
+            CHECK_PAYLOAD_SIZE(SYS_STATUS);
+            rover.send_extended_status1(chan);
+            CHECK_PAYLOAD_SIZE(POWER_STATUS);
+            send_power_status();
+        }
         break;
 
     case MSG_EXTENDED_STATUS2:

APMrover2/Rover.h

@@ -207,6 +207,9 @@ private:
     AP_Mount camera_mount;
 #endif
 
+    // true if initialisation has completed
+    bool initialised;
+
     // if USB is connected
     bool usb_connected;
 

APMrover2/system.cpp

@@ -217,6 +217,9 @@ void Rover::init_ardupilot()
 
     // disable safety if requested
     BoardConfig.init_safety();
+
+    // flag that initialisation has completed
+    initialised = true;
 }
 
 //*********************************************************************************