rib: fix initialization error in Service

refs #4723

Change-Id: Ibfe313a3e2f1b0e57ee81661aa387397101228f9
diff --git a/rib/service.hpp b/rib/service.hpp
index b39f5c6..a349787 100644
--- a/rib/service.hpp
+++ b/rib/service.hpp
@@ -86,7 +86,9 @@
   get();
 
 private:
-  Service(ndn::KeyChain& keyChain, shared_ptr<ndn::Transport> localNfdTransport);
+  template<typename ConfigParseFunc>
+  Service(ndn::KeyChain& keyChain, shared_ptr<ndn::Transport> localNfdTransport,
+          const ConfigParseFunc& configParse);
 
   void
   processConfig(const ConfigSection& section, bool isDryRun, const std::string& filename);
@@ -97,9 +99,6 @@
   void
   applyConfig(const ConfigSection& section, const std::string& filename);
 
-  void
-  initialize();
-
 private:
   static Service* s_instance;