message: Update URL for libsodium src in amazon.dockerfile.
diff: @@ -18,7 +18,7 @@ RUN \
  spectool
  RUN cd /tmp && \
  - curl https://download.libsodium.org/libsodium/releases/libsodium-1.0.12.tar.gz | tar -xz && \
  + curl https://download.libsodium.org/libsodium/releases/old/libsodium-1.0.12.tar.gz | tar -xz && \
  cd /tmp/libsodium-1.0.12 && \
  ./configure && \
  make && \
  