Hi simplyGD,
Also, you can copy/paste the \components\com_community\templates\jomsocial\layouts\friends folder into the \templates\socialize\html\com_community\layouts folder and open the list.php file in the friends folder, find the line 49 to remove the following code:
<div onclick="window.location='<?php echo CRoute::_('index.php?option=com_community&view=friends&task=invite'); ?>';" class="joms-button--add">
<?php echo Text::_('COM_COMMUNITY_INVITE_FRIENDS'); ?>
</div>