message: Added parameter for amount of build threads. Default (for DockerHub) is 1 but if build host with multiple cores is used, value could be increased
diff: ### At first perform source build ###
  FROM hlxeasy/spectre-builder-part2:latest as build
  +# Build parameters
  +ARG BUILD_THREADS="1"
  +
  +# Runtime parameters
  +ENV BUILD_THREADS=$BUILD_THREADS
  +
  COPY . /spectre
  RUN cd /spectre \
  && mkdir db4.8 leveldb tor \
  && ./autogen.sh \
  && ./configure \
  - && make -j6
  + && make -j${BUILD_THREADS}
  # --enable-gui \
  # --with-qt5=/usr/include/x86_64-linux-gnu/qt5 \
  