update comment

src/http/modules/ngx_http_limit_req_module.c

diff --git a/src/http/modules/ngx_http_limit_req_module.c b/src/http/modules/ngx_http_limit_req_module.c
index 94b6eba..16fe622 100644
--- a/src/http/modules/ngx_http_limit_req_module.c
+++ b/src/http/modules/ngx_http_limit_req_module.c
@@ -513,7 +513,7 @@
      * set by ngx_pcalloc():
      *
      *     conf->shm_zone = NULL;
-     *     conf->burst = 0.0;
+     *     conf->burst = 0;
      *     conf->nodelay = 0;
      */