Fix code scanning alert issue #1357 (#1499)

Author: JisanAR03

website/static/js/jquery.atwho.js

@@ -50,7 +50,7 @@
             _a = decodeURI("%C3%80");
             _y = decodeURI("%C3%BF");
             space = acceptSpaceBar ? "\ " : "";
-            regexp = new RegExp(flag + "([A-Za-z" + _a + "-" + _y + "0-9_" + space + "\'\.\+\-]*)$|" + flag + "([^\\x00-\\xff]*)$", 'gi');
+            regexp = new RegExp(flag + "([A-Za-z" + _a + "-" + _y + "0-9_" + space + '\'\.\+\-]*)$|' + flag + "([^\\x00-\\xff]*)$", 'gi');
             match = regexp.exec(subtext);
             if (match) {
                 return match[2] || match[1];