Face: In registerPrefix, make the default flags 3, and actually use them.
Face: In registerPrefix, make the default flags 3, and actually use them.

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