Fix humanize error message

Author: chipshort

packages/std/src/testing/mock.rs

@@ -151,7 +151,7 @@ impl Api for MockApi {
             Variant::Bech32,
         )
         .map(Addr::unchecked)
-        .map_err(|_| StdError::generic_err("Invalid canonical address"))
+        .map_err(|_| StdError::generic_err("Invalid bech32 prefix"))
     }
 
     fn secp256k1_verify(

packages/vm/src/testing/mock.rs

@@ -165,7 +165,7 @@ impl BackendApi for MockApi {
         try_br!((validate_length(canonical), gas_info));
 
         let result = encode(bech32_prefix, canonical.to_base32(), Variant::Bech32)
-            .map_err(|_| BackendError::user_err("Invalid canonical address"));
+            .map_err(|_| BackendError::user_err("Invalid bech32 prefix"));
 
         (result, gas_info)
     }