Fixed: Error reading PDF file

Fixes READARR-6P

src/NzbDrone.Core/MediaFiles/EbookTagService.cs

@@ -350,11 +350,13 @@ namespace NzbDrone.Core.MediaFiles
             try
             {
                 var book = PdfReader.Open(file, PdfDocumentOpenMode.InformationOnly);
+                if (book.Info != null)
+                {
                     result.Authors = new List<string> { book.Info.Author };
                     result.BookTitle = book.Info.Title;
 
                     _logger.Trace(book.Info.ToJson());
-                _logger.Trace(book.CustomValues.ToJson());
+                }
             }
             catch (Exception e)
             {