restore lastSaved declaration

review.html

@@ -213,6 +213,7 @@ function reset() {
 function cur() { return ITEMS[i]; }
 function span() { return cur().spans[s]; }
 let WSIZES = [400, 800, 1600, Infinity], wi = 1, wc = null, plo = 0, phi = 0, needCenter = true;
+let lastSaved = '';
 function wlabel() { return WSIZES[wi] === Infinity ? 'full' : '±' + WSIZES[wi] / 2; }
 function render() {
   const o = cur();