Updated to laravel 6

app/Http/Kernel.php

@@ -29,6 +29,7 @@ class Kernel extends HttpKernel
             \Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse::class,
             \Illuminate\Session\Middleware\StartSession::class,
             \Illuminate\View\Middleware\ShareErrorsFromSession::class,
+            \Illuminate\Routing\Middleware\ThrottleRequests::class,
             \BookStack\Http\Middleware\VerifyCsrfToken::class,
             \Illuminate\Routing\Middleware\SubstituteBindings::class,
             \BookStack\Http\Middleware\Localization::class