Fix a few references to php5-fpm

Unless we really mean php5-fpm, let's just say php-fpm.

roles/nginx/templates/wordpress.j2

@@ -1,6 +1,6 @@
 
     # try for WordPress index.php in /
-    # fall back to index.php + args (passed to php5-fpm later)
+    # fall back to index.php + args (passed to php-fpm later)
     # also serves static files from the disk instead of passing to interpreter,
     location / {
         try_files $uri $uri/ /index.php?$args;