Removed a double negation

Signed-off-by: emanuele <[email protected]>

Sources/Packages.php

@@ -645,7 +645,7 @@ function PackageInstallTest()
 		if (empty($thisAction))
 			continue;
 
-		if (isset($action['filename']) && !!file_exists($boarddir . '/Packages/temp/' . $context['base_path'] . $action['filename']))
+		if (isset($action['filename']) && !file_exists($boarddir . '/Packages/temp/' . $context['base_path'] . $action['filename']))
 		{
 			$context['has_failure'] = true;