Destroying a focused vis-timeline with clickToUse breaks other timelines

[fodpeter]

I have 2 timelines with clickToUse option. After the focused one is destroyed, I cannot interact with other timelines anymore.

Expected: I can focus other timelines and use them further.
Actual: Error in the console and other timelines are not focusable, zoomable.

Activator.js:126 Uncaught TypeError: Cannot read property 'unbind' of null
    at yD.deactivate (Activator.js:126)
    at yD.activate (Activator.js:102)
    at yD._onTapOverlay (Activator.js:139)

Reproduction:
https://jsbin.com/soyuqeg/edit?html,output

Component: vis-timeline
OS: Linux
Browser: Chrome

Other info:
I think this bug is caused by the Activator.js, that tries to deactivate the Activator instance in the current static field, but that instance was already destroyed (keycharm was set to null).
https://github.com/visjs/vis-timeline/blob/master/lib/shared/Activator.js#L126