Modified .gitignore file to ignore any files in web/config that end in "...

For different deployment environments, we move the contents of /web/config/site.php into a file in the same directory called local.php, then leave that file out of repo tracking. In site.php, we just load the local.php file - which is different for the given environment (prod, staging, dev/local).

Same scenario could apply for other usages. This commit simply updates the .gitignore file such that any files in /web/config that end in ".local.php" are ignored.