graphql-mesh-ws-issue

Description of graphql-mesh-ws-issue

How to reproduce:

1. Run yarn && yarn start. It runs source at port 3000 and grapql-mesh at 4000.
2. Go to http://localhost:3000/graphql and make sure query { hello } and subscription { greetings } returns values.
3. Open http://localhost:4000/graphql and execute same queries: { hello }, subscription { greetings }.

Expected behaviour: both of queries works correctly and returns values as source does. Current behaviour: subscription { greetings } returns "Hi" in 5 languages, { hello } returns null.