dapp build throws an error

```
 git clone git@github.com:EOSIO/eos-token-sale.git
cd eos-token-sale/
git submodule update --init --recursive
dapp build
```

returns
```
src/eos.sol:74:13: Error: Type uint256 is not implicitly convertible to expected type bool.
        if( limit ) assert( dailyTotals[today()] + msg.value < limit );
            ^---^
```