title: Remove last appeared comma in string using javascript
body: <p>I have a text</p>
  <blockquote>
  <p>test, text, 123, without last comma</p>
  </blockquote>
  <p>I need it to be</p>
  <blockquote>
  <p>test, text, 123 without last comma</p>
  </blockquote>
  <p>(no comma after 123). How to achieve this using JavaScript?</p>