nginx: add http_sub_module and other fix

Someone requested this module to be included, so create the config flag for it.

Signed-off-by: Ansuel Smith <ansuelsmth@gmail.com>

net/nginx/Config_ssl.in

@@ -194,6 +194,11 @@ config NGINX_HTTP_SECURE_LINK
 	bool
 	prompt "Enable HTTP secure link module"
 	default n
+
+config NGINX_HTTP_SUB
+	bool
+	prompt "Enable HTTP sub module"
+	default n
 	
 config NGINX_HEADERS_MORE
 	bool