docs: site-example: site.conf: fix typo

docs/site-example/site.conf

@@ -3,7 +3,7 @@
 -- Take a look at the documentation located at
 -- http://gluon.readthedocs.org/ for details.
 --
--- This configuration will not work as it. You're required to make
+-- This configuration will not work as is. You're required to make
 -- community specific changes to it!
 {
   -- Used for generated hostnames, e.g. freifunk-abcdef123456. (optional)