Update composer.json, fixing license for packagist

composer.json

@@ -3,7 +3,7 @@
 	"type": "typo3-cms-extension",
 	"description": "Embed YouTube Videos of a Playlist or Channel",
 	"homepage": "https://www.sgalinski.de",
-	"license": "GPL-2.0+",
+	"license": "GPL-2.0-or-later",
 	"version": "1.1.2",
 	"require": {
 		"typo3/cms-core": "7.6.0 - 8.7.99"