title: Validation is not getting triggered for multi-select component - Formio
body: <p>I'm using Select component which allows multiple values to be selected by the user.</p>
  <p>Though Formio has required error message display as an inbuilt functionality, I've used custom validation to display the required error message based on some parameters and also to avoid asterisk symbol near the label.
  The error message got correctly displayed if I have used inbuilt functionality, but the validation is not getting triggered if the select component has no options selected and its correctly working if any of the options got selected.</p>
  <p>The custom validation is correctly working and my required error message got correctly displayed if the same select component does not allowed multiple values.</p>