server.extras fix
diff --git a/nginx/server.sls b/nginx/server.sls
index 14ac15a..72d2e2c 100644
--- a/nginx/server.sls
+++ b/nginx/server.sls
@@ -9,7 +9,7 @@
   pkg.installed:
   - names: {{ server.pkgs }}
 
-{%- if server.extras %}
+{%- if server.extras is defined %}
 nginx_extra_packages:
   pkg.installed:
   - name: nginx-extras