Update the text expected in the GraphiQL test

The original one changed when updating to the latest GraphiQL.

Author: chrzaszcz

big_tests/tests/graphql_SUITE.erl

@@ -147,7 +147,7 @@ can_load_graphiql(Config) ->
     Ep = ?config(schema_endpoint, Config),
     {Status, Html} = get_graphiql_website(Ep),
     ?assertEqual({<<"200">>, <<"OK">>}, Status),
-    ?assertNotEqual(nomatch, binary:match(Html, <<"Loading...">>)).
+    ?assertNotEqual(nomatch, binary:match(Html, <<"MongooseIM GraphiQL">>)).
 
 user_checks_auth(Config) ->
     Ep = ?config(schema_endpoint, Config),