MMI-3265 Fix Syndication service

Author: Fosol

services/net/syndication/SyndicationAction.cs

@@ -464,7 +464,13 @@ private async Task<SyndicationFeed> GetFeedAsync(Uri url, IIngestActionManager m
         {
             try
             {
-                using var xmlr = XmlReader.Create(new StringReader(data));
+                var settings = new XmlReaderSettings()
+                {
+                    IgnoreComments = false,
+                    IgnoreWhitespace = true,
+                    DtdProcessing = DtdProcessing.Parse,
+                };
+                using var xmlr = XmlReader.Create(new StringReader(data), settings);
                 var feed = SyndicationFeed.Load(xmlr);
                 return feed;
             }