Do not bundle default system_config (prefer built-in defaults)

Inside the bundle, those files are read-only, anyway.
This alleviates us from generating/updating the files with whenever
the built-in default changes and also makes architecture dependent
default-config (compile time #defines) work.

tools/linux_packaging/build

@@ -620,8 +620,6 @@ cp $BUILD_ROOT/gtk2_ardour/default_ui_config $Etc
 
 mkdir ${Shared}/icons
 mkdir ${Shared}/resources
-cp ../../system_config $Etc/system_config
-cp ../../instant.xml $Shared/instant.xml
 cp ../../gtk2_ardour/icons/*.png ${Shared}/icons
 cp -r ../../gtk2_ardour/icons/cursor_* ${Shared}/icons/
 cp ../../gtk2_ardour/ArdourMono.ttf $Shared