Bulk change headers in MPD

[Roland Melkert]

...and btw, maybe this kind of MPD structure issue (duplicated NOFILE) could be catch up and corrected by LDCad cleanup?

The duplicate NOFILE will be ignored during loading (generates a warning in the logfile).

The internals will handle it as 'unknown/garbage' content which is preserved for forwards compatibility's sake but otherwise totally ignored.

In short the cleanup will do nothing to fix it as these lines are hidden to it