src: Small improvements

Change-Id: I9850cd6ec2330482915f815d94a2ac2ccaeae7f1
diff --git a/daemon/mgmt/manager-base.cpp b/daemon/mgmt/manager-base.cpp
index 114e818..60f3bc9 100644
--- a/daemon/mgmt/manager-base.cpp
+++ b/daemon/mgmt/manager-base.cpp
@@ -118,7 +118,7 @@
 ManagerBase::onCommandValidationFailed(const shared_ptr<const Interest>& command,
                                        const std::string& error)
 {
-  NFD_LOG_DEBUG("command result: unauthorized command: " << *command);
+  NFD_LOG_DEBUG("command result: unauthorized command: " << *command << " (" << error << ")");
   sendResponse(command->getName(), 403, "Unauthorized command");
 }