Typo on query

There's a typo on the schema of the rentals contract: https://github.com/decentraland/rentals-graph/blob/main/schema.graphql#L46

Which is then used here: https://github.com/decentraland/signatures-server/blob/283bd4b21c2541d67474508c78a7cb442a105011/src/ports/rentals/component.ts#L218

I'm leaving this issue here just to keep track of it, and to fix it next time we need to deploy signature-server + rentals-subgraph together.

Typo is siNGer instead of siGNer.