patch for plotutils Portfile

[mike@…]

The attached patch fixes the following plotutils install error, by replacing "opendarwin::lt" with "macports:yves:lt" in the Portfile:

Warning: No mirror sites on file for class opendarwin
--->  Fetching plotutils
--->  Attempting to fetch plotutils-2.4.1.tar.gz from http://ftp.gnu.org/gnu/plotutils
Error: No defined site for tag: lt, using master_sites
--->  Attempting to fetch ltconfig13 from http://ftp.gnu.org/gnu/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.gnu.org/gnu/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.uu.net/archive/systems/gnu/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.funet.fi/pub/gnu/prep/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.kddlabs.co.jp/pub/gnu/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.dti.ad.jp/pub/GNU/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.informatik.hu-berlin.de/pub/gnu/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.lip6.fr/pub/gnu/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.chg.ru/pub/gnu/plotutils
--->  Attempting to fetch ltconfig13 from ftp://ftp.mirror.ac.uk/sites/ftp.gnu.org/gnu/plotutils
--->  Attempting to fetch ltconfig13 from http://svn.macports.org/repository/macports/distfiles/plotutils
--->  Attempting to fetch ltconfig13 from http://svn.macports.org/repository/macports/distfiles/general/
--->  Attempting to fetch ltconfig13 from http://svn.macports.org/repository/macports/downloads/plotutils
Error: Target org.macports.fetch returned: fetch failed

[sfiera@…]

There's a more general problem of missing ltconfig/ltmain which I've collected into #12551. This bug is now a duplicate (I'm not just applying the patch, because I think that the master_sites should become 'macports:lt:lt' instead)