MEDIUM: ssl: capture the supported_versions extension from Client Hello

Activate the capture of the TLS supported_versions extension from the
Client Hello. This list is stored in the ssl_capture buffer when the
global option "tune.ssl.capture-cipherlist-size" is enabled.

include/haproxy/ssl_sock-t.h

@@ -219,6 +219,8 @@ struct ssl_capture {
 	uint ec_offset;
 	uint ec_formats_offset;
 	uchar ec_formats_len;
+	uchar supver_len;
+	uint supver_offset;
 	char data[VAR_ARRAY];
 };