Only return AsconTimeout in the aqadapter if no characters have been read.

Otherwise the DevQueueTask will skip fetching the reply.

site_ansto/hardsup/sct_asyncqueue.c

@@ -191,7 +191,11 @@ static int scaqaProtHandler(Ascon *a)
       return 0;
     }
     if (pp->txn.transWait < 0) {
+      if (GetDynStringLength(a->rdBuffer) == 0) {
         a->state = AsconTimeout;
+      } else {
+        a->state = AsconReadDone;
+      }
     } else if (pp->txn.transWait == 0) {
       a->state = AsconReadDone;
     }