Remove icon on mainpage.

static/index.html

@@ -24,7 +24,7 @@
       </form>
   
       <div id="public-groups" class="groups">
-        <h2>Public groups <i class="fa fa-users" aria-hidden="true"></i></h2>
+        <h2>Public groups</h2>
   
         <table id="public-groups-table"></table>
       </div>