bugfix: fixed build failures with OpenSSL older than 0.9.8f. thanks FFCZ for the report in openresty#413.

Author: agentzh

src/ngx_http_lua_socket_tcp.c

@@ -1289,13 +1289,23 @@ ngx_http_lua_socket_tcp_sslhandshake(lua_State *L)
                                "lua ssl server name: \"%*s\"", name.len,
                                name.data);
 
+#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME
+
                 if (SSL_set_tlsext_host_name(c->ssl->connection, name.data)
                     == 0)
                 {
                     lua_pushnil(L);
                     lua_pushliteral(L, "SSL_set_tlsext_host_name failed");
                     return 2;
                 }
+
+#else
+
+               ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
+                              "lua socket SNI disabled because the current "
+                              "version of OpenSSL lacks the support");
+
+#endif
             }
 
             if (n >= 4) {