Moved config loading to index.php

As `index.php` is the entry point of the webapp, loading configuration
data from the `config.ini` should take place there. This makes testing
easier, since a properly formatted `config.ini` (whose values are
overriden anyway) is no longer needed.

index.php

@@ -11,5 +11,9 @@ if (!ini_get('date.timezone')) {
 }
 
 require 'vendor/autoload.php';
+
+// Load configuration
+$config = GitList\Config::fromFile('config.ini');
+
 $app = require 'boot.php';
-$app->run();
+$app->run();