Changed autodetection of SiteURL (#3764)

* Changed autoconfiguration of SiteURL to be done on every request

* Added SiteURL to system console

webapp/components/create_team/components/team_url.jsx

@@ -105,7 +105,7 @@ export default class TeamUrl extends React.Component {
             nameDivClass += ' has-error';
         }
 
-        const title = `${window.mm_config.SiteURL}/`;
+        const title = `${Utils.getSiteURL()}/`;
         const urlTooltip = (
             <Tooltip id='urlTooltip'>{title}</Tooltip>
         );