add --with-http_image_filter_module to ./configure --help
diff --git a/auto/options b/auto/options
index 742a9f8..3b3ee0f 100644
--- a/auto/options
+++ b/auto/options
@@ -309,6 +309,7 @@
--with-http_realip_module enable ngx_http_realip_module
--with-http_addition_module enable ngx_http_addition_module
--with-http_xslt_module enable ngx_http_xslt_module
+ --with-http_image_filter_module enable ngx_http_image_filter_module
--with-http_sub_module enable ngx_http_sub_module
--with-http_dav_module enable ngx_http_dav_module
--with-http_flv_module enable ngx_http_flv_module
