Stub status: corrected the "stub_status" directive.

The "stub_status" directive does not require an argument.
diff --git a/src/http/modules/ngx_http_stub_status_module.c b/src/http/modules/ngx_http_stub_status_module.c
index f4f5888..dd68358 100644
--- a/src/http/modules/ngx_http_stub_status_module.c
+++ b/src/http/modules/ngx_http_stub_status_module.c
@@ -21,7 +21,7 @@
 static ngx_command_t  ngx_http_status_commands[] = {
 
     { ngx_string("stub_status"),
-      NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_FLAG,
+      NGX_HTTP_SRV_CONF|NGX_HTTP_LOC_CONF|NGX_CONF_NOARGS|NGX_CONF_TAKE1,
       ngx_http_set_stub_status,
       0,
       0,