not every change requires a revision bump

[Joshua Root]

Ref:
<http://trac.macports.org/changeset/73050>
<http://trac.macports.org/changeset/73056>

In these changesets, the universal variant is being enabled and a build
failure on i386 is being fixed. Neither of these warrant a rev bump. The
question to ask yourself is: Does a user who already has this port
installed want to rebuild it after this change? If yes, rev bump. If no,
don't.

- Josh