Add check for selecting option from the dropdown

[MIchaelMainer]

Line 133 -- added !$(this).hasClass('is-disabled') to check that the currently selected option is not disabled. Current behavior is the disabled option raises a change event. Updated behavior is to check that the option is disabled and not raise a change event on a disabled option.

Trimmed whitespace

[msftclas]

Hi @MIchaelMainer, I'm your friendly neighborhood Microsoft Pull Request Bot (You can call me MSBOT). Thanks for your contribution!

It looks like you're a Microsoft contributor (Michael Mainer). If you're full-time, we DON'T require a Contribution License Agreement. If you are a vendor, please DO sign the electronic Contribution License Agreement. It will take 2 minutes and there's no faxing! https://cla.microsoft.com.

TTYL, MSBOT;

[mikewheaton]

Good idea, we shouldn't fire an event if the option is disabled. Looks good to me. One more approver and we can merge it in.

[wdo3650]

@MIchaelMainer thanks for spotting this. Looks good to me.