move config_local.php out of the way of the user's configuration

git-svn-id: https://svn.code.sf.net/p/squirrelmail/code/trunk/squirrelmail@10415 7612ce4b-ef26-0410-bec9-ea0150e637f0

diff --git a/config/config_local.php b/config/config_local.example.php
similarity index 100%
rename from config/config_local.php
rename to config/config_local.example.php