Issue being fixed or feature implemented

We don't use tags in https://github.com/dashpay/dash-detached-sigs repo, we use branches so git describe fails...

What was done?

Add --always option to fallback to commit hash. Could do

git_head_version() {
    git -C "$1" rev-parse --short=12 HEAD`
}

instead but using describe allows us to start using tags one day with no additional patches.

How Has This Been Tested?

Breaking Changes

Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have added or updated relevant unit/integration/functional/e2e tests
• I have made corresponding changes to the documentation
• I have assigned this pull request to a milestone (for repository code-owners and collaborators only)