Fix afterFetchCallback Promise Condition

[juan-gunawan]

Somehow, async-await-to-promises mangled the previous condition to the one below, which is completely wrong.

if (!(_this5.state.isLoading === false)) {
          return Promise.resolve().then(function () {
            return cache.resolve(query);
          }).then(function () {
            return new Promise(function (resolve) {
              return _this2.props.afterFetchCallback(resolve, cache.getContents());
            });
          }).then(function () {
            if (typeof _this5.props.afterFetchCallback === "function") ;

            _this5.setState({
              isLoading: false
            });
          })
}

Instead, had to move the afterFetchCallback checking into the Promise.