[gsettings] Fix error in gsettings-schema-convert --help
[gsettings] Fix error in gsettings-schema-convert --help

The simple format can always be chosen.

GNOME/gconf,GNOME/gconf,hyperair/gconf-gdbus,Distrotech/GConf,GNOME/gconf,hyperair/gconf-gdbus,hyperair/gconf-gdbus,hyperair/gconf-gdbus,Distrotech/GConf,Distrotech/GConf,GNOME/gconf,Distrotech/GConf