clarify support email in tx commit failed error [skip ci]

lib/entities/default_settings_migration.dart

@@ -37,7 +37,7 @@ const havenDefaultNodeUri = 'nodes.havenprotocol.org:443';
 const ethereumDefaultNodeUri = 'ethereum-rpc.publicnode.com';
 const polygonDefaultNodeUri = 'polygon-bor-rpc.publicnode.com';
 const cakeWalletBitcoinCashDefaultNodeUri = 'bitcoincash.stackwallet.com:50002';
-const nanoDefaultNodeUri = 'nano.nownodes.io';
+const nanoDefaultNodeUri = 'rpc.nano.to';
 const nanoDefaultPowNodeUri = 'rpc.nano.to';
 const solanaDefaultNodeUri = 'solana-mainnet.core.chainstack.com';
 const tronDefaultNodeUri = 'api.trongrid.io';

lib/view_model/send/send_view_model.dart

@@ -846,7 +846,7 @@ abstract class SendViewModelBase extends WalletChangeListenerViewModel with Stor
       if (error.errorMessage != null && error.errorMessage!.contains("no peers replied")) {
         return S.current.tx_commit_failed_no_peers;
       }
-      return "${S.current.tx_commit_failed}${error.errorMessage != null ? "\n\n${error.errorMessage}" : ""}";
+      return "${S.current.tx_commit_failed}\nsupport@cakewallet.com${error.errorMessage != null ? "\n\n${error.errorMessage}" : ""}";
     }
     if (error is TransactionCommitFailedDustChange) {
       return S.current.tx_rejected_dust_change;