ca tool: allow to answer Certificate download interest with implicit digest

Change-Id: Ie8a747ef7485df33c5316160d01fd7733bf8efc2
diff --git a/tools/ndncert-ca-server.cpp b/tools/ndncert-ca-server.cpp
index f803a97..697960f 100644
--- a/tools/ndncert-ca-server.cpp
+++ b/tools/ndncert-ca-server.cpp
@@ -149,7 +149,7 @@
             return;
           }
           for (const auto& item : cachedCertificates) {
-            if (interestName.isPrefixOf(item.getName())) {
+            if (interestName.isPrefixOf(item.getFullName())) {
               face.put(item);
               return;
             }