message: Update install_db4.sh
diff: @@ -6,7 +6,7 @@ export LC_ALL=C
  set -e
  if [ -z "${1}" ]; then
  - echo "Usage: ./install_db4.sh <base-dir> [<extra-bdb-configure-flag> ...]"
  + echo "Usage: $0 <base-dir> [<extra-bdb-configure-flag> ...]"
  echo
  echo "Must specify a single argument: the directory in which db4 will be built."
  echo "This is probably \`pwd\` if you're at the root of the pivx repository."
  @@ -51,7 +51,7 @@ http_get() {
  if [ -f "${2}" ]; then
  echo "File ${2} already exists; not downloading again"
  elif check_exists curl; then
  - curl --insecure "${1}" -o "${2}"
  + curl --insecure --retry 5 "${1}" -o "${2}"
  else
  wget --no-check-certificate "${1}" -O "${2}"
  fi
  @@ -70,6 +70,20 @@ CLANG_CXX11_PATCH_HASH='7a9a47b03fd5fb93a16ef42235fa9512db9b0829cfc3bdf90edd3ec1
  http_get "${CLANG_CXX11_PATCH_URL}" clang.patch "${CLANG_CXX11_PATCH_HASH}"
  patch -p2 < clang.patch
  +# The packaged config.guess and config.sub are ancient (2009) and can cause build issues.
  +# Replace them with modern versions.
  +# See https://github.com/bitcoin/bitcoin/issues/16064
  +CONFIG_GUESS_URL='https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.guess;hb=55eaf3e779455c4e5cc9f82efb5278be8f8f900b'
  +CONFIG_GUESS_HASH='2d1ff7bca773d2ec3c6217118129220fa72d8adda67c7d2bf79994b3129232c1'
  +CONFIG_SUB_URL='https://git.savannah.gnu.org/gitweb/?p=config.git;a=blob_plain;f=config.sub;hb=55eaf3e779455c4e5cc9f82efb5278be8f8f900b'
  +CONFIG_SUB_HASH='3a4befde9bcdf0fdb2763fc1bfa74e8696df94e1ad7aac8042d133c8ff1d2e32'
  +
  +rm -f "dist/config.guess"
  +rm -f "dist/config.sub"
  +
  +http_get "${CONFIG_GUESS_URL}" dist/config.guess "${CONFIG_GUESS_HASH}"
  +http_get "${CONFIG_SUB_URL}" dist/config.sub "${CONFIG_SUB_HASH}"
  +
  cd build_unix/
  "${BDB_PREFIX}/${BDB_VERSION}/dist/configure" \
  