Set default NotFound handler.

cmd/dwelling-upload/main.go

@@ -8,6 +8,7 @@ import (
 	"flag"
 	"fmt"
 	"log"
+	nethttp "net/http"
 	"net/netip"
 	"os"
 	"os/signal"
@@ -88,7 +89,9 @@ func main() {
 		*keepFileForHours, *limitStorage, *limitFileSize)
 	srv := http.NewHttpServer()
 
-	srv.SetNotFoundHandler(http.NotFound)
+	srv.SetNotFoundHandler(func(w nethttp.ResponseWriter, r *nethttp.Request) {
+		http.Error(w, r, nethttp.StatusNotFound, "")
+	})
 
 	srv.ServeStatic("/assets/*filepath", hand.AssetsFS())
 	srv.GET("/robots.txt", http.RobotsTxt)