Fix compatibility with older browsers in zxing-js#700

mebjas merged 2 commits intomebjas:mastermebjas/html5-qrcode:masterfrom

bilal-elchami:feature/188_Fix_globalThis_From_Preventing_Use_In_Older_Browsersbilal-elchami/html5-qrcode:feature/188_Fix_globalThis_From_Preventing_Use_In_Older_BrowsersCopy head branch name to clipboard