refactored CosmicDawn importer - now working!

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

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

@@ -8,7 +8,7 @@ function attachmentList(json){
     var attachments = document.getElementById('attachments');
     attachments.innerHTML = '';
     for (var attachment of json){
-        if (attachment.mime.startsWith('image')){
+        if (attachment.mime.startsWith('image')||attachment.url.includes('.jpg')||attachment.url.includes('.png')||attachment.url.includes('.gif')){
             var img = document.createElement('img');
             img.src = attachment.url;
             attachments.appendChild(img);