Remove empty paragraphs from post_content

gistfile1.txt

<?php
/**
 * Remove empty paragraphs
 *
 * @param string $content the HTML markup of content
 *
 * @return string the HTML markup of content
 */
add_filter('the_content', function ($content) {

  if (!is_admin()) {
    $content = str_replace('<p></p>', '', $content);
    $content = str_replace('<p>&nbsp;</p>', '', $content);
  }
  return $content;

});