"nasty" output on stderr if closed project is in workspace

The following code in QtUtils creates "nasty" output on stderr if you have a closed
project in your workspace

public static boolean isQtProject(IProject project) {
if (project == null)
return false;
try

{ return project.hasNature(QtNature.QT_NATURE_ID); } catch (CoreException e) { e.printStackTrace(); }
return false;
}

Since hasNature will create an exception if called on a closed project
A possible fix would be to add a check for project.isOpen

public static boolean isQtProject(IProject project) {
if (project == null)
return false;
if(!project.isOpen()){ return false; }
try { return project.hasNature(QtNature.QT_NATURE_ID); }

catch (CoreException e)

{ e.printStackTrace(); }

return false;
}