BUILD: ssl: switch LibreSSL to Fastly CDN

OpenBSD ftp is down, let us switch to CDN

(cherry picked from commit 67036530983f9f6ce9f597473700ac35bece22f7)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit f04f356f4ff3ed131a539dd08130d79406b4a9f9)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 89d772e3077e9d27caa045e5b2673f9b45bc67bc)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/scripts/build-ssl.sh b/scripts/build-ssl.sh
index e1d89a0..4934a4e 100755
--- a/scripts/build-ssl.sh
+++ b/scripts/build-ssl.sh
@@ -59,7 +59,7 @@
 download_libressl () {
     if [ ! -f "download-cache/libressl-${LIBRESSL_VERSION}.tar.gz" ]; then
         wget -P download-cache/ \
-	    "https://ftp.openbsd.org/pub/OpenBSD/LibreSSL/libressl-${LIBRESSL_VERSION}.tar.gz"
+	    "https://cdn.openbsd.org/pub/OpenBSD/LibreSSL/libressl-${LIBRESSL_VERSION}.tar.gz"
     fi
 }