dns/ddclient: Get rid of a wrong shebang statement

in bin/ddclient. It has double shebang line and one is
"#!/usr/local/local/bin/perl -w" This is definitely wrong.

Also bumped PORTREVISION due to package content change.

PR: 231277
Submitted by: koobs
Reported by: O. Hartmann <ohartmann@walstatt.org>
Approved by: maintainer
MFH: 2019Q4