wip(download): allow delay on downoads

issue #828

lib/Ravada/Request.pm

@@ -64,7 +64,7 @@ our %VALID_ARG = (
     ,rename_domain => { uid => 1, name => 1, id_domain => 1}
     ,set_driver => {uid => 1, id_domain => 1, id_option => 1}
     ,hybernate=> {uid => 1, id_domain => 1}
-    ,download => {uid => 2, id_iso => 1, id_vm => 2, verbose => 2}
+    ,download => {uid => 2, id_iso => 1, id_vm => 2, verbose => 2, delay => 2}
     ,refresh_storage => { id_vm => 2 }
     ,clone => { uid => 1, id_domain => 1, name => 1, memory => 2 }
     ,change_owner => {uid => 1, id_domain => 1}