fix(cpn): Not saving on MacOS unless .etx in filename (#2830)

MacOS companion does not save models if ".etx" extension not in filename.

Co-authored-by: Phil Mitchell <phil.a.mitchell@gmail.com>

companion/src/mdichild.cpp

@@ -1250,11 +1250,7 @@ bool MdiChild::saveAs(bool isNew)
 {
   forceNewFilename();
   QFileInfo fi(curFile);
-#ifdef __APPLE__
-  QString filter;
-#else
   QString filter(ETX_FILES_FILTER % YML_FILES_FILTER);
-#endif
 
   QString fileName = QFileDialog::getSaveFileName(this, tr("Save As"), g.eepromDir() + "/" + fi.fileName(), filter);
   if (fileName.isEmpty())