fix: use ZERO_ADDRESS constant for currencyAddress example (#655)

Author: d4mr

src/server/routes/backend-wallet/transfer.ts

@@ -39,7 +39,7 @@ const requestBodySchema = Type.Object({
   },
   currencyAddress: Type.Optional({
     ...AddressSchema,
-    examples: [constants.AddressZero],
+    examples: [ZERO_ADDRESS],
     description:
       "The token address to transfer. Omit to transfer the chain's native currency (e.g. ETH on Ethereum).",
   }),