Fix --force-sync help description
Fix --force-sync help description

From the repo sync help page as of the latest release v1.12.37, the
--force-sync option is used to overwrite an existing project git
directory if it needs to point to a different object directory.

Currently, the help uses the description for -f, --force-broken instead
of --force-sync.

jenkinsci/repo-plugin,Typz/repo-plugin,maksonlee/repo-plugin,Typz/repo-plugin,jenkinsci/repo-plugin,maksonlee/repo-plugin