fix one more export conflict false positive

Somehow forgot about the case where the current export db tree is the
same one in the export log, and it warned about an export conflict when
getting a file in that situation. Of course it's no conflict at all!

This commit was sponsored by Jochen Bartl on Patreon.

Database/Export.hs

@@ -218,9 +218,11 @@ updateExportTreeFromLog db@(ExportHandle _ u) =
 		l <- Log.getExport u
 		case Log.exportedTreeishes l of
 			[] -> return ExportUpdateSuccess
-			(new:[]) | new /= old -> do
+			(new:[]) 
+				| new /= old -> do
 					updateExportTree db old new
 					liftIO $ recordExportTreeCurrent db new
 					liftIO $ flushDbQueue db
 					return ExportUpdateSuccess
+				| new == old -> return ExportUpdateSuccess
 			_ts -> return ExportUpdateConflict