[Gui] fix locale issue with InputField

fixes the issue first reported here: https://github.com/FreeCAD/FreeCAD/pull/6364#issuecomment-1072886169

Now, since PR #6364 was merged, we must no longer remove the group separator.

(The issue broke for example the FEM results: https://forum.freecadweb.org/viewtopic.php?p=582524#p582524.)

src/Gui/InputField.cpp

@@ -710,7 +710,6 @@ void InputField::wheelEvent (QWheelEvent * event)
 
 void InputField::fixup(QString& input) const
 {
-    input.remove(locale().groupSeparator());
     if (locale().negativeSign() != QLatin1Char('-'))
         input.replace(locale().negativeSign(), QLatin1Char('-'));
     if (locale().positiveSign() != QLatin1Char('+'))