Ignore subscriptions with invalid url and keep ones with empty title.

if a channel if deleted (thus it has an empty title), it is imported in NewPipe anyway, so that if it becomes undeleted in the future, it will be shown in the app.

Author: Stypox

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/extractors/YoutubeSubscriptionExtractor.java

@@ -63,20 +63,10 @@ private List<SubscriptionItem> getItemsFromOPML(InputStream contentInputStream)
             String title = outline.attr("title");
             String xmlUrl = outline.attr("abs:xmlUrl");
 
-            if (title.isEmpty()) {
-                continue;
-            }
-
-            if (xmlUrl.isEmpty()) {
-                throw new InvalidSourceException("document has invalid entries");
-            }
-
             try {
                 String id = Parser.matchGroup1(ID_PATTERN, xmlUrl);
                 result.add(new SubscriptionItem(service.getServiceId(), BASE_CHANNEL_URL + id, title));
-            } catch (Parser.RegexException e) {
-                throw new InvalidSourceException("document has invalid entries", e);
-            }
+            } catch (Parser.RegexException ignored) { /* ignore invalid subscriptions */ }
         }
 
         return result;