fix(LoginDialog) added missing double quotes

modules/UI/authentication/LoginDialog.js

     return `
         <input name="username" type="text"
                class="input-control"
-               data-i18n="[placeholder]dialog.user
+               data-i18n="[placeholder]dialog.user"
                placeholder=${placeholder} autofocus>
         <input name="password" type="password"
                class="input-control"