Only convert overbar syntax on names, refdes and text.

In particular, don't try and convert filenames which may be in
windows format.

Fixes https://gitlab.com/kicad/code/kicad/issues/git

common/plugins/altium/altium_parser.cpp

@@ -157,6 +157,7 @@ std::map<wxString, wxString> ALTIUM_PARSER::ReadProperties()
         else
             value = wxString( valueS.c_str(), wxConvISO8859_1 );
 
+        if( key == wxT( "Designator" ) || key == wxT( "Name" ) || key == wxT( "Text" ) )
             value = AltiumPropertyToKiCadString( value.Trim() );
 
         kv.insert( { canonicalKey, value.Trim() } );