fix(dgraph): Add X-Dgraph-AuthToken to list of access control allowed…

… headers (#7311)

Fixes GRAPHQL-928

This would allow the user to do schema alter operations from the browser when they have Poor Man's auth enabled on Alpha.

(cherry picked from commit 4b3b2d9)

x/x.go

@@ -123,7 +123,7 @@ const (
 	// bulk load.
 	GroupIdFileName = "group_id"
 
-	AccessControlAllowedHeaders = "X-Dgraph-AccessToken, " +
+	AccessControlAllowedHeaders = "X-Dgraph-AccessToken, X-Dgraph-AuthToken, " +
 		"Content-Type, Content-Length, Accept-Encoding, Cache-Control, " +
 		"X-CSRF-Token, X-Auth-Token, X-Requested-With"
 	DgraphCostHeader = "Dgraph-TouchedUids"