assistant: call empathy_account_widget_get_default_display_name before actually creating the account
assistant: call empathy_account_widget_get_default_display_name before actually creating the account

This saves us a D-Bus call.

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