network: Fix warnings after removing a VPN
This is due to the object being accessed after being unreffed - connect the signal so it is removed when the object is finalized.
This regression was introduced in 93a269f8 when switching to GtkTemplate.
This is due to the object being accessed after being unreffed - connect the signal so it is removed when the object is finalized.
This regression was introduced in 93a269f8 when switching to GtkTemplate.