failing to update posix file permissions correctly even when this is supported

[perlundq]

$ mkdir dir
$ echo file > dir/file
$ yajsync -r dir/ dir.new
Warning: this software is still unstable and there might be data corruption bugs hiding. So use it only carefully at your own risk.
$ ls -l dir dir.new
dir:
total 4
-r--r--r-- 1 perl perl 5 Oct  6 23:26 file

dir.new:
total 4
-rw------- 1 perl perl 5 Oct  6 23:28 file

in this case dir.new/file is expected to have perms 0444