fixed bug: tag filter now ignoring letter case

Signed-off-by: Stephan Richter <s.richter@srsoftware.de>

de.srsoftware.cal.web/src/main/resources/script/index.js

@@ -184,11 +184,11 @@ function updateTagVisibility(){
     });
     var table = document.getElementById('eventlist');
     for (var tr of table.getElementsByTagName('tr')){
-        var classes = tr.getAttribute('class');
+        var classes = tr.getAttribute('class').toLowerCase();
         if (classes =='head') continue;
         var all = true;
         tags.forEach(tag => {
-            if (classes.indexOf(tag)<0) all = false;
+            if (classes.indexOf(tag.toLowerCase())<0) all = false;
         });
         tr.style.display = all ? 'table-row' : 'none';
     }