openvpn: update to 2.4.8

Backport two upstream commits that allow building
openvpn-openssl without OpenSSLs deprecated APIs.

Full changelog:
https://community.openvpn.net/openvpn/wiki/ChangesInOpenvpn24#OpenVPN2.4.8

Signed-off-by: Magnus Kroken <mkroken@gmail.com>

package/network/services/openvpn/patches/110-openssl-dont-use-deprecated-ssleay-symbols.patch

@@ -0,0 +1,58 @@
+From 17a476fd5c8cc49f1d103a50199e87ede76b1b67 Mon Sep 17 00:00:00 2001
+From: Steffan Karger <steffan@karger.me>
+Date: Sun, 26 Nov 2017 16:04:00 +0100
+Subject: [PATCH] openssl: don't use deprecated SSLEAY/SSLeay symbols
+
+Compiling our current master against OpenSSL 1.1 with
+-DOPENSSL_API_COMPAT=0x10100000L screams bloody murder.  This patch fixes
+the errors about the deprecated SSLEAY/SSLeay symbols and defines.
+
+Signed-off-by: Steffan Karger <steffan@karger.me>
+Acked-by: Gert Doering <gert@greenie.muc.de>
+Message-Id: <20171126150401.28565-1-steffan@karger.me>
+URL: https://www.mail-archive.com/openvpn-devel@lists.sourceforge.net/msg15934.html
+Signed-off-by: Gert Doering <gert@greenie.muc.de>
+---
+ configure.ac                 | 1 +
+ src/openvpn/openssl_compat.h | 8 ++++++++
+ src/openvpn/ssl_openssl.c    | 2 +-
+ 3 files changed, 10 insertions(+), 1 deletion(-)
+
+--- a/configure.ac
++++ b/configure.ac
+@@ -904,6 +904,7 @@ if test "${enable_crypto}" = "yes" -a "$
+ 			EVP_MD_CTX_free \
+ 			EVP_MD_CTX_reset \
+ 			EVP_CIPHER_CTX_reset \
++			OpenSSL_version \
+ 			SSL_CTX_get_default_passwd_cb \
+ 			SSL_CTX_get_default_passwd_cb_userdata \
+ 			SSL_CTX_set_security_level \
+--- a/src/openvpn/openssl_compat.h
++++ b/src/openvpn/openssl_compat.h
+@@ -689,6 +689,14 @@ EC_GROUP_order_bits(const EC_GROUP *grou
+ #endif
+ 
+ /* SSLeay symbols have been renamed in OpenSSL 1.1 */
++#ifndef OPENSSL_VERSION
++#define OPENSSL_VERSION SSLEAY_VERSION
++#endif
++
++#ifndef HAVE_OPENSSL_VERSION
++#define OpenSSL_version SSLeay_version
++#endif
++
+ #if !defined(RSA_F_RSA_OSSL_PRIVATE_ENCRYPT)
+ #define RSA_F_RSA_OSSL_PRIVATE_ENCRYPT       RSA_F_RSA_EAY_PRIVATE_ENCRYPT
+ #endif
+--- a/src/openvpn/ssl_openssl.c
++++ b/src/openvpn/ssl_openssl.c
+@@ -1977,7 +1977,7 @@ get_highest_preference_tls_cipher(char *
+ const char *
+ get_ssl_library_version(void)
+ {
+-    return SSLeay_version(SSLEAY_VERSION);
++    return OpenSSL_version(OPENSSL_VERSION);
+ }
+ 
+ #endif /* defined(ENABLE_CRYPTO) && defined(ENABLE_CRYPTO_OPENSSL) */