Don't send EOT

It was a bug that sending EOT when closing connection.

app/app.go

@@ -216,10 +216,6 @@ func (app *App) generateHandler() func(w http.ResponseWriter, r *http.Request) {
 
 		go func() {
 			<-exit
-			if app.PermitWrite {
-				fio.Write([]byte{4})
-			}
-			fio.Close()
 			conn.Close()
 			log.Printf("Connection closed: %s", r.RemoteAddr)
 		}()