Update attachments.js

added else condition to check if MAX_IMAGE_PIXEL is not set, so that it is possible to  upload attachments using drag-and-drop or Ctrl+V without setting the environmental-variable.
If this change is not allowed, please document in the wiki, that this is necessary for a fully-running wekan-instance

client/components/cards/attachments.js

@@ -131,6 +131,8 @@ Template.previewClipboardImagePopup.onRendered(() => {
             direct(results);
           },
         });
+       } else {
+        direct(results);
       }
     }
   };