Log Message:
The libxml2 version test in this thing believes that checking that
version A.B.C is at least D.E.F is to be done by checking A >= D, B >=
E, *and* C >= F. Therefore, it believes that the most recent libxml2
update, which is 2.8.0, is less than its minimum requirement 2.4.1.

Rather than trying to repair this curious logic, just patch the test
to always succeed, as pkgsrc always provides a suitable libxml2.