Don't throw with large size

[tomivirkki]

This change is 

[web-padawan]

Reviewed 1 of 2 files at r1, 1 of 1 files at r2.
Reviewable status: complete! all files reviewed, all discussions resolved (waiting on @tomivirkki)

[heruan]

Seems like it still throws, but in a different method:

Uncaught RangeError: Maximum call stack size exceeded
    at HTMLElement.clearCache (vaadin-combo-box-data-provider-mixin.html:170)
    at Object.comboBox.$connector.reset (comboBoxConnector.js:110)
    at Object.eval (eval at jt (client-D1AD34905AC1AA5B4DBECA8FB0306D92.cache.js:972), <anonymous>:3:33)

I'll open a new issue, as this is already merged.