SCRIPTS: create-release: show the correct origin name in suggested commands

create-release shows the next steps at the end and suggest to use
"git push origin master" but on my machine it's not "origin" so let's
determine it using git config and only use origin as a fall back.

(cherry picked from commit ff0c8424c87f1d702d98cdb593e6b701c7e61b15)
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed