Fix panic when Render method is not declared in smart contract

[yassinouider]

In function handleRealmRender, when the error returned by makeRequest is "Render not declared", the code tries to write to the res variable, which is nil. This causes a panic in the server.

Steps to reproduce:

1. Make a request to the server for a realm that has no Render() function
2. Observe the server panic

Fix:
I added the line "res = &abci.ResponseQuery{}" before writing to the res.Data variable. This creates an instance of abci.ResponseQuery and prevents the panic.

[yassinouider]

Hi @moul will realm without Render be allowed or should a check be applied before deploying them?

[moul]

A realm without Render makes sense.

We need to manage this case without panic.