Fix composer.json

Author: fabpot

src/Symfony/Component/Notifier/Bridge/Discord/composer.json

@@ -30,9 +30,5 @@
         ]
     },
     "minimum-stability": "dev",
-    "extra": {
-        "branch-alias": {
-            "dev-master": "5.2-dev"
-        }
-    }
+    "version": "5.2.x-dev"
 }