Handle text-overflow of the site selector

plugins/Zeitgeist/stylesheets/ui/_siteSelect.less

@@ -47,6 +47,10 @@
   text-decoration: none;
   background: none;
   cursor: default;
+  max-width: 110px;
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
 }
 
 .sites_autocomplete--dropdown .custom_select_main_link {