Event still firing twice on iOS

[agisboye]

dbf3782 fixed the issue with events firing twice on iOS, but it only resolved the issue when tapping the checkbox itself. Tapping the adjacent label still makes the event fire twice.

[agisboye]

Here's the culprit:

https://github.com/bradmartin/nativescript-checkbox/blob/dbf3782d71859735e2d4859fb1fc6a3322b70450/checkbox.ios.ts#L157

The tap handler on the label is being added every time the checkbox loads. It should be added either once or at least be removed on each corresponding unload call. I've made a PR (#31), which takes the latter approach.

[triniwiz]

@agisboye yeah i forgot to remove that tap listener since i don't use the label 😄 👍

[agisboye]

No problem 😄 Would you mind pushing a new release with the fix?