Update some code for Heroku.

app/Providers/AppServiceProvider.php

@@ -25,7 +25,7 @@ namespace FireflyIII\Providers;
 use Illuminate\Support\Facades\Schema;
 use Illuminate\Support\ServiceProvider;
 use Laravel\Passport\Passport;
-
+use URL;
 /**
  * @codeCoverageIgnore
  * Class AppServiceProvider.
@@ -38,6 +38,9 @@ class AppServiceProvider extends ServiceProvider
     public function boot(): void
     {
         Schema::defaultStringLength(191);
+        if('heroku' === env('APP_ENV')) {
+            URL::forceScheme('https');
+        }
     }
 
     /**