Making CakePHP able to run inside a Phar file

Using realpath() for configuration files breaks the lookup path for pahr files,
we really don't need to resolve symbolic links in this specific case.

src/Core/Configure/FileConfigTrait.php

@@ -56,7 +56,7 @@ protected function _getFilePath($key, $checkExists = false)
 
         $file .= $this->_extension;
 
-        if ($checkExists && !is_file(realpath($file))) {
+        if ($checkExists && !is_file($file)) {
             throw new Exception(sprintf('Could not load configuration file: %s', $file));
         }