WebUI: Add torrents paused because of errors in Paused and Download list

Torrents paused because of errors are considered as torrents paused and in
download in the regular UI. Do the same in the WebUI for consistency.

Closes #2319.

src/webui/qtorrentfilter.cpp

@@ -74,7 +74,8 @@ bool QTorrentFilter::isTorrentDownloading(const QTorrentHandle &h) const
             || state == QTorrentState::StalledDownloading
             || state == QTorrentState::CheckingDownloading
             || state == QTorrentState::PausedDownloading
-            || state == QTorrentState::QueuedDownloading;
+            || state == QTorrentState::QueuedDownloading
+            || state == QTorrentState::Error;
 }
 
 bool QTorrentFilter::isTorrentCompleted(const QTorrentHandle &h) const
@@ -93,7 +94,8 @@ bool QTorrentFilter::isTorrentPaused(const QTorrentHandle &h) const
     const QTorrentState state = h.torrentState();
 
     return state == QTorrentState::PausedDownloading
-            || state == QTorrentState::PausedUploading;
+            || state == QTorrentState::PausedUploading
+            || state == QTorrentState::Error;
 }
 
 bool QTorrentFilter::isTorrentActive(const QTorrentHandle &h) const