git-hook: Catch tab indentation also for makefiles

[Tamas Zolnai]

Hi there,

I just noticed that for makefiles (*.mk) git does not check whether the commit contains tab indentation. As I know we use spaces also for makefiles for indentation, right? So I added a patch changing pre-commit hook to check tab also for makfiles:
https://gerrit.libreoffice.org/#/c/41897/
I hope it's ok. I don't know who used to care of git stuff.

Thanks,
Tamás