[Web::Handler::HTTPDaemon] compensate for Rakudo fix

It's no longer Callable &app, just &app. Rakudo used to get this wrong,
but now it gets it right, so we must, too.

lib/Web/Handler/HTTPDaemon.pm

@@ -3,7 +3,7 @@ use v6;
 use HTTP::Daemon;
 
 class Web::Handler::HTTPDaemon {
-    method run(Callable &app, :$port = 8888) {
+    method run(&app, :$port = 8888) {
         my HTTP::Daemon $d .= new(LocalPort => $port);
         while my $c = $d.accept and my HTTP::Request $r = $c.get_request {
             my $qs = $r.url.path ~~ / '?' (.*) $/ ?? $0 !! '';