Fix : in old projects without the conductors formula, the conductors texts aren't loaded and displayed
Fix it in method void Conductor::refreshText()
git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@4825 bfdf4180-ca20-0410-9c96-a3a8aa849046
The change is apply for every conductors in the same potential
git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@4814 bfdf4180-ca20-0410-9c96-a3a8aa849046