query-node: update graphql api port to query

tests/network-tests/.env

@@ -1,7 +1,7 @@
 # Address of the Joystream node.
 NODE_URL = ws://127.0.0.1:9944
 # Address of the Joystream query node.
-QUERY_NODE_URL = http://127.0.0.1:8080/graphql
+QUERY_NODE_URL = http://127.0.0.1:8081/graphql
 # Account which is expected to provide sufficient funds to test accounts.
 TREASURY_ACCOUNT_URI = //Alice
 # Sudo Account