security: In key-chain.cpp, need to qualify func_lib with ndn namespace.
security: In key-chain.cpp, need to qualify func_lib with ndn namespace.

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