Fix for the user-selected configurations not being checked in the viewer

When you have an ivy.xml that extends another module and that other
module defines some configurations, it occurred that calling

  settingsSetupTab.init(conf.isSettingsProjectSpecific(),
conf.getIvySettingsSetup());
        
would cause the configurations being set again, because the
ModifyListener of ivyUserDirEditor would fire and cause
reinitialization.