fix(en): do not log error when whitelisted_tokens_for_aa is not suppo…

…rted (#1600)

## What ❔

Do not log error when whitelisted_tokens_for_aa is not supported

## Why ❔

Old main node doesn't have this method and EN shouldn't spam errors in
this case.

## Checklist

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<!-- For draft PRs check the boxes as you complete them. -->

- [ ] PR title corresponds to the body of PR (we generate changelog
entries from PRs).
- [ ] Tests for the changes have been added / updated.
- [ ] Documentation comments have been added / updated.
- [ ] Code has been formatted via `zk fmt` and `zk lint`.
- [ ] Spellcheck has been run via `zk spellcheck`.
- [ ] Linkcheck has been run via `zk linkcheck`.

core/bin/external_node/src/main.rs

@@ -51,7 +51,7 @@ use zksync_state::PostgresStorageCaches;
 use zksync_storage::RocksDB;
 use zksync_types::L2ChainId;
 use zksync_utils::wait_for_tasks::ManagedTasks;
-use zksync_web3_decl::{client::L2Client, namespaces::EnNamespaceClient};
+use zksync_web3_decl::{client::L2Client, jsonrpsee, namespaces::EnNamespaceClient};
 
 use crate::{
     config::{observability::observability_config_from_env, ExternalNodeConfig},
@@ -445,6 +445,11 @@ async fn run_api(
                     Ok(tokens) => {
                         *whitelisted_tokens_for_aa_cache_clone.write().await = tokens;
                     }
+                    Err(jsonrpsee::core::client::Error::Call(error))
+                        if error.code() == jsonrpsee::types::error::METHOD_NOT_FOUND_CODE =>
+                    {
+                        // Method is not supported by the main node, do nothing.
+                    }
                     Err(err) => {
                         tracing::error!(
                             "Failed to query `whitelisted_tokens_for_aa`, error: {err:?}"