bug #6709 Update AdminRouterSubscriber.php (damien-louis)

This PR was squashed before being merged into the 4.x branch.

Discussion
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Update AdminRouterSubscriber.php

Relate issue: #6707

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Commits
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03d51dd Update AdminRouterSubscriber.php

src/EventListener/AdminRouterSubscriber.php

@@ -172,11 +172,13 @@ public function onKernelRequest(RequestEvent $event): void
             }
 
             $prettyUrlRoute = $this->adminRouteGenerator->findRouteName($dashboardControllerFqcn, $crudControllerFqcn, $request->query->get(EA::CRUD_ACTION, ''));
-            $request->query->remove(EA::CRUD_CONTROLLER_FQCN);
+            if (null !== $prettyUrlRoute) {
+                $request->query->remove(EA::CRUD_CONTROLLER_FQCN);
 
-            $event->setResponse(new RedirectResponse($this->urlGenerator->generate($prettyUrlRoute, $request->query->all())));
+                $event->setResponse(new RedirectResponse($this->urlGenerator->generate($prettyUrlRoute, $request->query->all())));
 
-            return;
+                return;
+            }
         }
 
         if (null === $dashboardControllerInstance = $this->getDashboardControllerInstance($dashboardControllerFqcn, $request)) {