Use standard BLOB,KEY,NACK as contentType instead of customized types

Change-Id: I792e19b8f1e2aa359605da44074fc25bf7963a9a
diff --git a/tests/unit/database-test-data.cpp b/tests/unit/database-test-data.cpp
index 4b1de42..c3f6e07 100644
--- a/tests/unit/database-test-data.cpp
+++ b/tests/unit/database-test-data.cpp
@@ -80,7 +80,7 @@
     name::Component qType(label::NDNS_ITERATIVE_QUERY);
     NdnsContentType contentType = NDNS_RESP;
     if (type == label::CERT_RR_TYPE) {
-      contentType = NDNS_BLOB;
+      contentType = NDNS_KEY;
       qType = label::NDNS_CERT_QUERY;
     } else if (type == label::NS_RR_TYPE) {
       contentType = NDNS_LINK;