Increase browser compatibility

src/js/vanity.js

@@ -97,7 +97,7 @@ onmessage = function (event) {
     try {
         getVanityWallet(input.hex, input.checksum, input.suffix, (message) => postMessage(message));
     } catch (err) {
-        self.postMessage({error: err.toString()}, '*');
+        self.postMessage({error: err.toString()});
     }
 };
 

src/vue/Input.vue

@@ -66,8 +66,9 @@
 
     function mixCase(str) {
         let ret = '';
-        for (let i of str) {
-            ret += Math.random() < 0.5 ? i.toUpperCase() : i.toLowerCase();
+        for (let i = 0; i < str.length; i++) {
+            const l = str.substr(i, 1);
+            ret += Math.random() < 0.5 ? l.toUpperCase() : l.toLowerCase();
         }
         return ret;
     }