Log Message:
py-mercurial: update to 4.4.1.

1.1. Notable changes

    Git and Subversion subrepos have been disabled by default to
    mitigate a potential security risk if files overlapping with
    a subrepo managed to be committed to a repository.
    Subrepos are now more paranoid about symlink traversal.
    The share extension handles drive letters on Windows better.

It is possible that a specially malformed repository can cause Git
subrepositories to run arbitrary code in the form of a
.git/hooks/post-update script checked in to the repository in
Mercurial 4.4 and earlier. Typical use of Mercurial prevents
construction of such repositories, but they can be created
programmatically.