Fix crash on incremental bundling with warnings

For example, if the HEAD is excluded:

    warning: ref 'refs/heads/master' is excluded by the rev-list options
    warning: ref 'HEAD' is excluded by the rev-list options
    fatal: Refusing to create empty bundle.

The fatal message always appears last (though that's of course undocumented).

codearchiver/modules/git.py

@@ -119,7 +119,7 @@ class Git(codearchiver.core.Module):
 		objectsToExclude = baseBundleObjects & commitsAndTags
 		input = ''.join(f'^{o}\n' for o in objectsToExclude).encode('ascii')
 		status, _, stderr = codearchiver.subprocess.run_with_log(cmd, cwd = directory, input = input, check = False)
-		if status == 128 and stderr == 'fatal: Refusing to create empty bundle.\n':
+		if status == 128 and (stderr == 'fatal: Refusing to create empty bundle.\n' or stderr.endswith('\nfatal: Refusing to create empty bundle.\n')):
 			# Manually write an empty bundle instead
 			# Cf. Documentation/technical/bundle-format.txt and Documentation/technical/pack-format.txt in git's repository for details on the formats
 			_logger.info('Writing empty bundle directly instead')