use shutil.move instead of os.rename to move file

[DvdGiessen]

On my system the temporary directory is a tmpfs mount:

$ mount | grep /tmp
tmpfs on /tmp type tmpfs (rw,nosuid,nodev,size=31678096k,nr_inodes=1048576,inode64)

This breaks changeprefix.py because os.rename cannot move files across filesystem boundaries:

$ ./scripts/changeprefix.py --git lfs lfs2
Traceback (most recent call last):
  File "./scripts/changeprefix.py", line 76, in changefile
    os.rename(to_path, from_path)
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^
OSError: [Errno 18] Invalid cross-device link: '/tmp/tmp51imc7k8' -> '.gitattributes'

A simple fix is to use shutil.move which does handle this correctly.

[geky-bot]

Tests passed ✓, Code: 17116 B (+0.0%), Stack: 1448 B (+0.0%), Structs: 812 B (+0.0%)

	Code	Stack	Structs		Coverage
Default	17116 B (+0.0%)	1448 B (+0.0%)	812 B (+0.0%)	Lines	2432/2594 lines (+0.0%)
Readonly	6230 B (+0.0%)	448 B (+0.0%)	812 B (+0.0%)	Branches	1279/1610 branches (-0.0%)
Threadsafe	17968 B (+0.0%)	1448 B (+0.0%)	820 B (+0.0%)		Benchmarks
Multiversion	17188 B (+0.0%)	1448 B (+0.0%)	816 B (+0.0%)	Readed	29369693876 B (+0.0%)
Migrate	18780 B (+0.0%)	1752 B (+0.0%)	816 B (+0.0%)	Proged	1482874766 B (+0.0%)
Error-asserts	17896 B (+0.0%)	1440 B (+0.0%)	812 B (+0.0%)	Erased	1568888832 B (+0.0%)

[geky]

Oh interesting. I have the same setup on my machine, so I guess I haven't ran changeprefix.py locally in... years... I usually just checkout the v2-prefix branch.

Thanks for the PR! I'm going to sneak this into the in-flight release.