sdk: small fix to allow LC to start on registries without TNs

If starting with userDepositContractAddress as contract's entrypoint,
it'd crash if the `TokenNetworkRegistry` didn't have any registered
`TokenNetwork`. This fix allows the client to start, so one can use
`registerToken` to register a TN from this session.

raiden-ts/CHANGELOG.md

@@ -8,8 +8,10 @@
 - [#2965] Remove `options.subkey` on certain `Raiden` public methods; if you need to force subkey or main account usage for single txs, set `config.subkey` then reset after tx is sent; default behavior is kept
 
 ### Fixed
+- [#2913] Fix crash when starting client with `userDepositContractAddress` as contracts entrypoint on a `TokenNetworkRegistry` with no registered tokens yet
 - [#2963] Don't set channel as `closing` upon `channelClose.request`, allowing user to cancel Metamask's prompt and keep an usable channel; Channel becomes `closing` only after tx is sent
 
+[#2913]: https://github.com/raiden-network/light-client/issues/2913
 [#2949]: https://github.com/raiden-network/light-client/issues/2949
 [#2952]: https://github.com/raiden-network/light-client/issues/2952
 [#2953]: https://github.com/raiden-network/light-client/pull/2953

raiden-ts/src/helpers.ts

@@ -410,14 +410,14 @@ export async function fetchContractsInfo(
   const serviceRegistry = (await monitoringServiceContract.service_registry()) as Address;
 
   const toBlock = await provider.getBlockNumber();
-  let firstBlock = await firstValueFrom(
+  const firstBlock = await firstValueFrom(
     getLogsByChunk$(provider, {
       ...tokenNetworkRegistryContract.filters.TokenNetworkCreated(null, null),
       fromBlock: 1,
       toBlock,
     }).pipe(pluck('blockNumber'), filter(isntNil)),
+    { defaultValue: toBlock },
   );
-  firstBlock ??= 0;
 
   const oneToN = (await userDepositContract.one_to_n_address()) as Address;