Lower RFsim timeout when no UE connected

This will lead to quicker drop of the UE context in the gNB once it
disconnected from RFsim.

radio/rfsimulator/simulator.c

@@ -817,7 +817,7 @@ static int rfsimulator_read(openair0_device *device, openair0_timestamp *ptimest
     if ( t->nextRxTstamp == 0)
       LOG_W(HW,"No connected device, generating void samples...\n");
 
-    if (!flushInput(t, 10,  nsamps)) {
+    if (!flushInput(t, 1,  nsamps)) {
       for (int x=0; x < nbAnt; x++)
         memset(samplesVoid[x],0,sampleToByte(nsamps,1));