message: improving Dockerfile.build
diff: -FROM node:12-alpine AS builder
  -RUN apk add python build-base sqlite-dev sqlite-libs vips-dev
  +FROM node:12-alpine3.10 AS builder
  +RUN apk add --update-cache --repository https://alpine.global.ssl.fastly.net/alpine/v3.10/community/ \
  + python build-base sqlite-dev sqlite-libs vips-dev fftw-dev gcc g++ make libc6-compat
  COPY pigallery2-release /app
  WORKDIR /app
  RUN npm install --unsafe-perm
  @@ -9,7 +10,7 @@ RUN mkdir -p /app/data/config && \
  mkdir -p /app/data/tmp
  -FROM node:12-alpine
  +FROM node:12-alpine3.10
  WORKDIR /app
  # command line arg orverride the config.json with these settings
  ENTRYPOINT ["npm", "start", "--", \
  @@ -21,7 +22,8 @@ ENTRYPOINT ["npm", "start", "--", \
  "--Server-Media-tempFolder=/app/data/tmp"]
  EXPOSE 80
  ENV NODE_ENV=production
  -RUN apk add ffmpeg
  +RUN apk add --update-cache --repository https://alpine.global.ssl.fastly.net/alpine/v3.10/community/ \
  + vips ffmpeg
  COPY --from=builder /app /app
  VOLUME ["/app/data/config", "/app/data/db", "/app/data/images", "/app/data/tmp"]
  HEALTHCHECK --interval=30s --timeout=20s --retries=4 --start-period=60s \
  