account-widget: check that the apply button actually exist before modifying it
account-widget: check that the apply button actually exist before modifying it

It's not created in the 'simple' version of the widget. (#607455)

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