fix git diff list for files with spaces

[minrk]

git uses \t as delimiter. Without this, split fails with "Too many values to unpack", as \s+ catches spaces in filenames.

I don't know if there are situations where git would use a different character.

Example git output line:

'R099\tfile name.md\tnew file name.md'

[Starlight220]

There should be a -0 or -Z flag that makes git use a \0 as a delimiter.