message: [examples/model] Make erc20 example compile again
diff: // along with pDSL. If not, see <http://www.gnu.org/licenses/>.
  #![no_std]
  -#![feature(const_str_as_bytes)]
  use pdsl_core::{
  - env::srml::{
  + env::{
  Address,
  Balance,
  },
  @@ -66,7 +65,7 @@ fn instantiate() -> impl Contract {
  .on_msg::<BalanceOf>(|env, owner| {
  env.state.balances[&owner]
  })
  - .on_msg_mut::<Transfer>(|env, (to: Address, amount: Address)| {
  + .on_msg_mut::<Transfer>(|env, (to, amount)| {
  let from = env.caller();
  let balance_from = env.state.balances[&from];
  let balance_to = env.state.balances[&to];
  