empathy-accounts: prepare the AM in app_command_line_cb
empathy-accounts: prepare the AM in app_command_line_cb

We just need to prepare it in the main instance; there is no point doing it
the other ones as they will just re-invoke the main one and exit.

https://bugzilla.gnome.org/show_bug.cgi?id=662504

Distrotech/telepathy-account-widgets,Distrotech/telepathy-account-widgets,GNOME/telepathy-account-widgets,GNOME/telepathy-account-widgets,GNOME/telepathy-account-widgets