Zoom and Pan: simplify waitForOpts

    // Wait until opts loaded

    async function waitForOpts() {

        return new Promise(resolve => {

            const checkInterval = setInterval(() => {

                if (window.opts && Object.keys(window.opts).length !== 0) {

                    clearInterval(checkInterval);

                    resolve(window.opts);

        for (;;) {

            if (window.opts && Object.keys(window.opts).length) {

                return window.opts;

            }

            await new Promise(resolve => setTimeout(resolve, 100));

        }

            }, 100);

        });

    }

    // Check is hotkey valid