Apply patch for CVE-2013-6393 [1] to fix heap-based buffer overflow when
parsing YAML tags.

This is the libyaml-indent-column-overflow-v2.patch patch
from the ticket.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1033990
pkg-info: Don't show -f when using -E alone.

This is invoked by *-depends: target in bsd.port.mk