Fix block processing job created twice when processing missing parent block (#67)

* Fix block processing job created twice in watcher

* Fix block processing job for missing parent blocks

packages/graph-node/test/subgraph/example1/src/mapping.ts

@@ -143,7 +143,6 @@ export function testStructEthCall (): void {
   log.debug('In test struct eth call', []);
 
   // Bind the contract to the address that emitted the event.
-  // TODO: Address.fromString throws error in WASM module instantiation.
   const contractAddress = dataSource.address();
   const contract = Example1.bind(contractAddress);