message: add validation check to targets
diff: @@ -67,7 +67,7 @@ import "./style.css";
  name="target"
  label="Target"
  value={this.props.command ? this.props.command.target : ""}
  - targets={this.props.command.targets}
  + targets={this.props.command ? this.props.command.targets : []}
  disabled={!this.props.command}
  onChange={this.props.command ? this.props.command.setTarget : null} />
  <FlatButton
  