update to 2.24.1
    
    Per the upstream release announcement¹, this release fixes "various
    security flaws, which allowed an attacker to overwrite arbitrary paths,
    remotely execute code, and/or overwrite files in the .git/ directory
    etc.  See the release notes attached for the list for their descriptions
    and CVE identifiers."
    
    Refer to the 2.14.6 release notes² for details on these vulnerabilities.
    
    ¹ https://lore.kernel.org/git/xmqqr21cqcn9.fsf@gitster-ct.c.googlers.com/
    ² https://www.kernel.org/pub/software/scm/git/docs/RelNotes/2.14.6.txt