LU-7328 misc: no non-ASCII characters in commit messages

LU-7328 misc: no non-ASCII characters in commit messages

Some commit messages have control characters, or fancy quotation
marks, or mdash hyphens or similar, and this messes up the display
of "git log" and other tools depending on the current locale and
character set used in the terminal.

Add a check into commit-msg to reject commit messages that have
non-ASCII characters. This does not apply to characters used in
the Signed-off-by: or similar fields that list people's names.

Test-Parameters: trivial
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: I99d0954a68f8a5391195553ebf4b69181b6991f2
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/53304
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Timothy Day <timday@amazon.com>
Reviewed-by: Arshad Hussain <arshad.hussain@aeoncomputing.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>