chore: speed-up OpenSSL build

only uses 2 threads to limit workload on Travis CI where the environment is not really stable.

Author: mayeut

docker/build_scripts/build-openssl.sh

@@ -40,12 +40,17 @@ fi
 
 PREFIX=/opt/_internal/openssl-${OPENSSL_VERSION%.*}
 
+PARALLEL_BUILDS=
+if [ "$(nproc)" -ge 2 ]; then
+	PARALLEL_BUILDS=-j2
+fi
+
 fetch_source "${OPENSSL_ROOT}.tar.gz" "${OPENSSL_DOWNLOAD_URL}"
 check_sha256sum "${OPENSSL_ROOT}.tar.gz" "${OPENSSL_HASH}"
 tar -xzf "${OPENSSL_ROOT}.tar.gz"
 pushd "${OPENSSL_ROOT}"
 ./Configure "--prefix=${PREFIX}" "--openssldir=${PREFIX}" --libdir=lib CPPFLAGS="${MANYLINUX_CPPFLAGS}" CFLAGS="${MANYLINUX_CFLAGS}" CXXFLAGS="${MANYLINUX_CXXFLAGS}" LDFLAGS="${MANYLINUX_LDFLAGS} -Wl,-rpath,\$(LIBRPATH)" > /dev/null
-make > /dev/null
+make ${PARALLEL_BUILDS} > /dev/null
 make install_sw > /dev/null
 popd
 rm -rf "${OPENSSL_ROOT}" "${OPENSSL_ROOT}.tar.gz"