build: migrate to C++17

Change-Id: Ic9f09efd20b608bfcb713fd319834b2666cf6242
diff --git a/src/hello-protocol.cpp b/src/hello-protocol.cpp
index fac4458..ec03da7 100644
--- a/src/hello-protocol.cpp
+++ b/src/hello-protocol.cpp
@@ -21,8 +21,8 @@
 #include "hello-protocol.hpp"
 #include "nlsr.hpp"
 #include "lsdb.hpp"
-#include "utility/name-helper.hpp"
 #include "logger.hpp"
+#include "utility/name-helper.hpp"
 
 #include <ndn-cxx/encoding/nfd-constants.hpp>
 
@@ -30,9 +30,6 @@
 
 INIT_LOGGER(HelloProtocol);
 
-const std::string HelloProtocol::INFO_COMPONENT = "INFO";
-const std::string HelloProtocol::NLSR_COMPONENT = "nlsr";
-
 HelloProtocol::HelloProtocol(ndn::Face& face, ndn::KeyChain& keyChain,
                              ConfParameter& confParam, RoutingTable& routingTable,
                              Lsdb& lsdb)
@@ -204,9 +201,9 @@
   }
 }
 
-  // This is the first function that incoming Hello data will
-  // see. This checks if the data appears to be signed, and passes it
-  // on to validate the content of the data.
+// This is the first function that incoming Hello data will
+// see. This checks if the data appears to be signed, and passes it
+// on to validate the content of the data.
 void
 HelloProtocol::onContent(const ndn::Interest& interest, const ndn::Data& data)
 {