security: in key-chain.cpp for bind with _1, if using std::function, need namespace placeholders. Refs #1063.
security: in key-chain.cpp for bind with _1, if using std::function, need namespace placeholders. Refs #1063.

cawka/packaging-ndn-cpp-dev,cawka/packaging-ndn-cpp,cawka/packaging-ndn-cpp-dev,cawka/packaging-ndn-cpp-dev,cawka/packaging-ndn-cpp,cawka/packaging-ndn-cpp,cawka/packaging-ndn-cpp,cawka/packaging-ndn-cpp-dev