Minor text improvement

src/main/java/at/ac/uibk/gitsearch/repository/search/MetaDataRepository.java

@@ -821,7 +821,7 @@ public class MetaDataRepository {
         // temporary for backward compatibility!
         String oldExerciseId = convertToPreviousId(exerciseId);
         if (oldExerciseId.equals(exerciseId)) {
-            throw new NotFoundException(" Exercise with id " + exerciseId + " not found?");
+            throw new NotFoundException(" Exercise with id " + exerciseId + " not found or no access rights?");
         } else {
             return getExerciseById(oldExerciseId, user);
         }