GCS_MAVLINK: cope with AP_Frsky_Telem being created after init

may be created by the FPort backend

libraries/GCS_MAVLink/GCS_Common.cpp

@@ -1775,6 +1775,7 @@ void GCS::send_statustext(MAV_SEVERITY severity, uint8_t dest_bitmask, const cha
         logger->Write_Message(text);
     }
 
+    frsky = AP::frsky_telem();
     if (frsky != nullptr) {
         frsky->queue_message(severity, text);
     }