Make CredentialRepositoryV1ToV2Adapter package-private

Author: emlun

webauthn-server-core/src/main/java/com/yubico/webauthn/CredentialRepositoryV1ToV2Adapter.java

@@ -8,7 +8,7 @@
 import lombok.AllArgsConstructor;
 
 @AllArgsConstructor
-public class CredentialRepositoryV1ToV2Adapter
+class CredentialRepositoryV1ToV2Adapter
     implements CredentialRepositoryV2<RegisteredCredential>, UsernameRepository {
 
   private final CredentialRepository inner;