Disabling AJAX refresh icon

Go to:

AdminCP > Look & Feel > skin name > includeVars

search for :

ipb.templates['ajax_loading'] = "<div id="ajax_loading"><img src="%7B$this-%3Esettings[" img_url']}="" ajax_loading.gif'="" alt="" + ipb.lang[" loading']="" +="" "'=""></div>";

and either comment it out or delete it and add this:

ipb.templates['ajax_loading'] = "";