Adding mutationObserver without checking if site is on whitelist first

[AidanSpeakss]

It seems I could make a performance improvement by only adding the mutation observer if a site is not on the whitelist, this way the mutation observer is never called on whitelisted sites.

Line 85 to 97 in background.js

const mutationObserver = new MutationObserver(function (mutations) {
    mutations.forEach(function (mutation) {
        if(mutation.target.hasChildNodes())
            childrenEater(mutation.target);
        else
            piiSearch(mutation.target);
    });
});