Fix string concatenation when returning to the previous page in the browser

public/js/common.js

@@ -76,7 +76,7 @@ ForkBB.common = (function (doc, win) {
         var inps = doc.querySelectorAll("input[type='hidden'][name='nekot']");
 
         for (var i = 0; i < inps.length; i++) {
-            inps[i].value += (inps[i].parentNode.querySelector("input[type='hidden'][name='token']").value.replace(/\D/g, '').replace(/(......).*/, '$1'));
+            inps[i].value = (inps[i].parentNode.querySelector("input[type='hidden'][name='token']").value.replace(/\D/g, '').replace(/(......).*/, '$1'));
         }
     }