Removes wait for app boot for routes registration

Waiting for app to boot causes the routes to register late, at the end of the routes list.
May cause overriding use defined routes.
Or in my case, a "catch all" route which caught the `_grid-sortable_` route (because it was prior in the routes list).

Author: vladkucherov

src/GridSortableServiceProvider.php

@@ -23,14 +23,12 @@ public function boot(GridSortable $extension)
             );
         }
 
-        $this->app->booted(function () {
-            GridSortable::routes(__DIR__.'/../routes/web.php');
-        });
+        GridSortable::routes(__DIR__.'/../routes/web.php');
 
         Admin::booting(function () {
             Admin::headerJs('vendor/laravel-admin-ext/grid-sortable/jquery-ui.min.js');
         });
 
         $extension->install();
     }
-}
+}