sepolicy: do not fail when file_contexts.local or .subs do not exist

On a system without any file context customizations, "sepolicy gui"
fails to load because it tries to read a non-existing file:

    FileNotFoundError: [Errno 2] No such file or directory:
    '/etc/selinux/refpolicy-git/contexts/files/file_contexts.local'

Once this issue is fixed, another one is triggered:

    FileNotFoundError: [Errno 2] No such file or directory:
    '/etc/selinux/refpolicy-git/contexts/files/file_contexts.subs

Use try/except to catch these exceptions and use OSError/errno.ENOENT to
keep the code compatible with Python 2.

Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
1 file changed