fix building by bcc/etc introduced in r2038

src/http/ngx_http_special_response.c

diff --git a/src/http/ngx_http_special_response.c b/src/http/ngx_http_special_response.c
index 3b653fc..6127149 100644
--- a/src/http/ngx_http_special_response.c
+++ b/src/http/ngx_http_special_response.c
@@ -332,7 +332,7 @@
     ngx_http_err_page_t       *err_page;
     ngx_http_core_loc_conf_t  *clcf;
 
-    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
+    ngx_log_debug3(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                    "http special response: %d, \"%V?%V\"",
                    error, &r->uri, &r->args);