fix: unreadable error logs (#122)

Author: melisaguevara

packages/indexer/src/data-indexing/service/Indexer.ts

@@ -75,7 +75,7 @@ export class Indexer {
           notificationPath: "across-indexer-error",
           blockRangeResult,
           dataIdentifier: this.dataHandler.getDataIdentifier(),
-          error,
+          error: JSON.stringify(error),
         });
         blockRangeProcessedSuccessfully = false;
       } finally {