switch from div to span

git-svn-id: https://redmine.imt-atlantique.fr/svn/xaal/code/Python/branches/fork@1752 b32b6428-25c9-4566-ad07-03861ab6144f

apps/dashboard/xaal/dashboard/static/tags/thermometer.tag

 <thermometer>
 
-<div class="thermometer">
-<!-- <i class="fa fa-thermometer-half temperature" aria-hidden="true"></i> -->
+<span class="thermometer">
 <span class="temperature">{ temperature }°C</span>
-<!-- <span class="addr">addr : {addr}</span> -->
-</div>
+</span>
 
 <script>
 this.addr = opts.xaal_addr