Another bugfix for SharedData::updateHostAndPortEnv().

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2478 ba6dc0ae-232f-0410-883f-9ebac64fc565
Bugfix for 2478.

git-svn-id: svn://svn.code.sf.net/p/dmtcp/code/trunk@2479 ba6dc0ae-232f-0410-883f-9ebac64fc565