title: How to disable flag in "ngx-intl-tel-input" lib?
body: <p>how to disable flag in "ngx-intl-tel-input" lib, I disable input field in form has ngx-intl-tel-input but not disable flag.
  Please see issue fixed "<a href="https://github.com/webcat12345/ngx-intl-tel-input/issues/205" rel="nofollow noreferrer">https://github.com/webcat12345/ngx-intl-tel-input/issues/205</a>"</p>