modsecurity: correctly set response status in header filter

Author: pracj3am

src/ngx_http_modsecurity_header_filter.c

@@ -92,9 +92,11 @@ ngx_http_modsecurity_header_filter(ngx_http_request_t *r)
     msc_process_response_headers(ctx->modsec_transaction, r->headers_out.status,
                                  http_protocol);
     ngx_http_modsecurity_pcre_malloc_done(old_pool);
+
     rc = ngx_http_modsecurity_process_intervention(ctx->modsec_transaction, r);
     if (rc > 0) {
-        return rc;
+        r->headers_out.status = rc;
+        r->headers_out.status_line.len = 0;
     }
 
     return ngx_http_next_header_filter(r);