removed obsolete composer repo

composer.json

@@ -8,12 +8,6 @@
         }
     ],
     "license": "GPL-2.0",
-    "repositories": [
-        {
-            "type": "composer",
-            "url": "https://packages.zendframework.com/"
-        }
-    ],
     "require": {
         "aferrandini/phpqrcode": "1.0.1",
         "jasig/phpcas": "1.3.3",