entry: re-introduce the 'account-path' prop but as read-only
entry: re-introduce the 'account-path' prop but as read-only

Clients are not supposed to create their own entries so they don't have to set
this property.

freedesktop-unofficial-mirror/telepathy__telepathy-logger,freedesktop-unofficial-mirror/telepathy__telepathy-logger,freedesktop-unofficial-mirror/telepathy__telepathy-logger