Get a child theme from http://vamtam.com/child-themes/ and copy templates/shortcodes/team_member.php from the main theme to the child (remember to create the missing directories). In the newly copied file, find this line:
<a href="<?php echo $$icon?>" title=""><?php echo do_shortcode('[icon name="'.$icon_name.'"]'); ?></a>
and replace it with:
<a href="<?php echo esc_url( $$icon ) ?>" title="" target="_blank"><?php echo do_shortcode('[icon name="'.$icon_name.'"]'); ?></a>