Fixed "ERROR: Using ${var} in strings is deprecated, use {$var} instead"

src/Application/Actions/User/ViewUserAction.php

@@ -16,7 +16,7 @@ protected function action(): Response
         $userId = (int) $this->resolveArg('id');
         $user = $this->userRepository->findUserOfId($userId);
 
-        $this->logger->info("User of id `{$userId}` was viewed.");
+        $this->logger->info("User of id " . $userId . " was viewed.");
 
         return $this->respondWithData($user);
     }