Dots nav doesn't display on resize if the page is loaded first on viewport where slider is disabled

[marko-hologram]

Issue description:
Navigation dots are not appearing after you resize the window if the slider was initialized on a viewport where slider is disabled in the config. For example if you set that the slider is disabled on viewport >768px, if you load the page on a viewport larger than that and then resize the browser to <768px the slider will initialize, but navigation dots won't appear.

Reloading the page on viewport <768px shows navigation dots and resizing the viewport to >768px and then back to <768px works as expected.

I've included a link to jsfiddle where it is demonstrated. Try to run the fiddle with result window set to >768px, then resize it to <768px and dots won't show. Now run it again with result window <768px, then resize it to >768px and back to <768px and it will work as expected.

Tested only on Windows for now, can test on MacOS in about 12 hours from now if it's needed.

I know browser resizing in session isn't that common, but considering everything else inits properly I consider this a bug.

Demo link/slider setting: https://jsfiddle.net/n429tape/

Tiny-slider version: 2.9.1
Browser name && version: Chrome Version 71.0.3578.98 && Version 72.0.3626.81 || Firefox 64 && 65 || Microsoft Edge 44.17763.1.0 (Microsoft EdgeHTML 18.17763)
OS name && version: Windows 10 (v. 1809)

[maksabuzyarov]

The problem is still relevant. This happens not only in the described case, but also when the slider is initialized in the viewport, where navigation is turned off nav: false and then resize the browser to the nav: true

Updated demo: https://jsfiddle.net/Lnm4swbe/1/