update license information, fix dependency

composer.json

@@ -23,7 +23,7 @@
   },
   "homepage": "https://www.oxidmodule.com/",
   "license": [
-    "proprietary"
+    "GPL-3.0-or-later"
   ],
   "extra": {
     "oxideshop": {
@@ -33,7 +33,7 @@
   },
   "require": {
     "php": ">=7.3",
-    "d3/ordermanager": "^5.0.4.0",
+    "d3/ordermanager": "^5.1",
     "d3/linkmobility4oxid": "^1.0"
   },
   "require-dev": {