BUILD: ssl: introduce fine guard for OpenSSL specific SCTL functions

SCTL (signed certificate timestamp list) specified in RFC6962
was implemented in c74ce24cd22e8c683ba0e5353c0762f8616e597d, let
us introduce macro HAVE_SSL_SCTL for the HAVE_SSL_SCTL sake,
which in turn is based on SN_ct_cert_scts, which comes in the same commit
diff --git a/include/haproxy/openssl-compat.h b/include/haproxy/openssl-compat.h
index 3fe58be..b5f05d1 100644
--- a/include/haproxy/openssl-compat.h
+++ b/include/haproxy/openssl-compat.h
@@ -57,6 +57,10 @@
 #define HAVE_SSL_CTX_get0_privatekey
 #endif
 
+#if (defined(SN_ct_cert_scts) && !defined(OPENSSL_NO_TLSEXT))
+#define HAVE_SSL_SCTL
+#endif
+
 #if (HA_OPENSSL_VERSION_NUMBER < 0x0090800fL)
 /* Functions present in OpenSSL 0.9.8, older not tested */
 static inline const unsigned char *SSL_SESSION_get_id(const SSL_SESSION *sess, unsigned int *sid_length)
diff --git a/src/ssl_ckch.c b/src/ssl_ckch.c
index f654b4b..8aa29bd 100644
--- a/src/ssl_ckch.c
+++ b/src/ssl_ckch.c
@@ -320,7 +320,7 @@
 		goto end;
 	}
 
-#if (HA_OPENSSL_VERSION_NUMBER >= 0x1000200fL && !defined OPENSSL_NO_TLSEXT && !defined OPENSSL_IS_BORINGSSL)
+#ifdef HAVE_SSL_SCTL
 	/* try to load the sctl file */
 	if (global_ssl.extra_files & SSL_GF_SCTL) {
 		struct stat st;
@@ -939,7 +939,7 @@
 	CERT_TYPE_OCSP,
 #endif
 	CERT_TYPE_ISSUER,
-#if (HA_OPENSSL_VERSION_NUMBER >= 0x1000200fL && !defined OPENSSL_NO_TLSEXT && !defined OPENSSL_IS_BORINGSSL)
+#ifdef HAVE_SSL_SCTL
 	CERT_TYPE_SCTL,
 #endif
 	CERT_TYPE_MAX,
@@ -956,7 +956,7 @@
 #if ((defined SSL_CTRL_SET_TLSEXT_STATUS_REQ_CB && !defined OPENSSL_NO_OCSP) || defined OPENSSL_IS_BORINGSSL)
 	[CERT_TYPE_OCSP]   = { "ocsp",    CERT_TYPE_OCSP,     &ssl_sock_load_ocsp_response_from_file },
 #endif
-#if (HA_OPENSSL_VERSION_NUMBER >= 0x1000200fL && !defined OPENSSL_NO_TLSEXT && !defined OPENSSL_IS_BORINGSSL)
+#ifdef HAVE_SSL_SCTL
 	[CERT_TYPE_SCTL]   = { "sctl",    CERT_TYPE_SCTL,     &ssl_sock_load_sctl_from_file },
 #endif
 	[CERT_TYPE_ISSUER] = { "issuer",  CERT_TYPE_ISSUER,   &ssl_sock_load_issuer_file_into_ckch },