If you try to clear the Livesearch when empty, it throws error in console

[kpagnat]

Hi everyone,

I have created a Fiddle that can reproduce the problem.
https://jsfiddle.net/dpzopfmw/

When input is already clear and you push back again, it throws an error 👍

bootstrap-select.js:246 Uncaught TypeError: Cannot read property 'replace' of undefined(…)

It seems the function normalizeToBase is not taking into consideration that "text" can be undefined.

Thanks

[markdon]

Also occurs and repeats when pressing many (any?) non-printable keys.