Added signature.clear
Added signature.clear

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