Activating scroll fails with an exception

[argasek]

Checklist

I'm using version [0.2.2]
My browser is: Chrome 68.0.3440.75

Description

An attempt to scroll fails with the following exception:
jquery-scrollTo.es.js:201 Uncaught DOMException: Failed to execute 'insertRule' on 'CSSStyleSheet': Cannot access StyleSheet to insertRule

This happens on the document.styleSheets[0].insertRule(rule, 0); line:

  insertRule(rule) {
    ...
    if (document.styleSheets && document.styleSheets.length) {
      document.styleSheets[0].insertRule(rule, 0);
    } else {
       ...
    }
  }

It fails, because first CSS stylesheet on my website is loaded from an external CDN, which means it's not accessible, and jquery-scrollTo blindly assumes otherwise.