s3, googlecloudstorage, azureblob: fix encoding issue with dir path comparison

`remote` has been converted ToStandardPath a few lines above, so `directory`
needs to be converted the same way in order to be compared properly. This was
spotted on `TestBisyncRemoteRemote/extended_filenames` for
`TestS3,directory_markers:` and `TestGoogleCloudStorage,directory_markers:`
which tripped over a directory name containing a Line Feed symbol.

backend/s3/s3.go

@@ -4065,7 +4065,7 @@ func (f *Fs) list(ctx context.Context, opt listOpt, fn listFn) error {
 					isDirectory = false
 				} else {
 					// Don't insert the root directory
-					if remote == opt.directory {
+					if remote == f.opt.Enc.ToStandardPath(opt.directory) {
 						continue
 					}
 				}