Fixed: Error checking if files should be deleted after import won't leave import in limbo

(cherry picked from commit 88ad6f9544110a2e825ebe6b2cde17e9f05475cc)

Closes #824

src/NzbDrone.Core/MediaFiles/DownloadedBooksImportService.cs

@@ -115,7 +115,9 @@ namespace NzbDrone.Core.MediaFiles
             try
             {
                 var bookFiles = _diskScanService.GetBookFiles(directoryInfo.FullName);
-                var rarFiles = _diskProvider.GetFiles(directoryInfo.FullName, true).Where(f => Path.GetExtension(f).Equals(".rar", StringComparison.OrdinalIgnoreCase));
+                var rarFiles = _diskProvider.GetFiles(directoryInfo.FullName, true).Where(f =>
+                    Path.GetExtension(f).Equals(".rar",
+                        StringComparison.OrdinalIgnoreCase));
 
                 foreach (var bookFile in bookFiles)
                 {
@@ -144,6 +146,11 @@ namespace NzbDrone.Core.MediaFiles
                 _logger.Debug(e, "Folder {0} has already been removed", directoryInfo.FullName);
                 return false;
             }
+            catch (Exception e)
+            {
+                _logger.Debug(e, "Unable to determine whether folder {0} should be removed", directoryInfo.FullName);
+                return false;
+            }
         }
 
         private List<ImportResult> ProcessFolder(IDirectoryInfo directoryInfo, ImportMode importMode, DownloadClientItem downloadClientItem)