Fix for self-DoS in Security-txt Chrome Extension.

@sp1d3rs found a self-DoS vulnerability in the Security-txt Chrome Extension. He was also kind enough to provide a fix wich you can find on [GitHub](https://github.com/securitytxt/chrome-extension/pull/2). We merged @sp1d3rs' fix when he submitted a PR. We later decided that it was better to stop …

function getSecuritytxt(url, domain, tabid, i, messaged) {
    const consume = responseReader => {
    return responseReader.read().then(result => {
        //Only handle the first chunk.
        if (result.done || chunks == 1) { return; }
        const chunk = result.value;
        chunks++ …