remove unused file

overlay/grocy-env-variables.diff

@@ -1,25 +0,0 @@
-diff --git a/app.php b/app.php
-index bc5b1b3..26f7687 100644
---- a/app.php
-+++ b/app.php
-@@ -12,7 +12,7 @@ use Slim\Views\Blade;
- require_once __DIR__ . '/packages/autoload.php';
- 
- // Load config files
--require_once GROCY_DATAPATH . '/config.php';
-+require_once getenv('GROCY_CONFIG_FILE');
- require_once __DIR__ . '/config-dist.php'; // For not in own config defined values we use the default ones
- require_once __DIR__ . '/helpers/ConfigurationValidator.php';
- 
-diff --git a/helpers/PrerequisiteChecker.php b/helpers/PrerequisiteChecker.php
-index 8e12a5c..37b433d 100644
---- a/helpers/PrerequisiteChecker.php
-+++ b/helpers/PrerequisiteChecker.php
-@@ -18,7 +18,6 @@ class PrerequisiteChecker
- 	public function checkRequirements()
- 	{
- 		self::checkForPhpVersion();
--		self::checkForConfigFile();
- 		self::checkForConfigDistFile();
- 		self::checkForComposer();
- 		self::checkForPhpExtensions();