Cryptsetup git main default branch

Hi,

I changed the default branch name in cryptsetup git
   https://github.com/mbroz/cryptsetup
to "main" branch -  the former "master" branch will be keep in sync with it.

The same applies for mirror on GitHub (https://github.com/mbroz/cryptsetup).

It will stay this way at least for one year from now, so everything should work.
But better update your git or scripts now.

Thanks,
Milan