merge two onInterest callback into one

Change-Id: I82e8150239d795cb465ea2526624300590e4434c
diff --git a/tests/unit-tests/challenge-credential.t.cpp b/tests/unit-tests/challenge-credential.t.cpp
index 358175e..a4acddc 100644
--- a/tests/unit-tests/challenge-credential.t.cpp
+++ b/tests/unit-tests/challenge-credential.t.cpp
@@ -55,7 +55,7 @@
   auto identityA = addIdentity(Name("/example"));
   auto keyA = identityA.getDefaultKey();
   auto certA = key.getDefaultCertificate();
-  CertificateRequest request(Name("/example"), "123", REQUEST_TYPE_NEW, Status::BEFORE_CHALLENGE, certA);
+  CertificateRequest request(Name("/example"), "123", RequestType::NEW, Status::BEFORE_CHALLENGE, certA);
 
   // create requester's existing cert
   auto identityB = addIdentity(Name("/trust/cert"));