Please help hiding social media fields from the registration page

Need to hide social media fields from registration page - Facebook, Twitter, Google Plus and Linkedin

Plugin developers suggested modifying plugin's core files. After removing these fileds , the warning shows up:

Warning: Cannot modify header information - headers already sent by (output started at /wp-content/plugins/wp-jobhunt/templates/dashboards/candidate/templates_ajax_functions.php:1) in /wp-includes/pluggable.php on line 1195

Please advise