incus: Fix first use message on admin init #234

Job	Run time
Code	1m 32s
Documentation	2m 41s
Client (1.20.x, ubuntu-latest)	1m 3s
System (1.20.x, cluster, dir)	1m 25s
Client (1.20.x, macos-latest)	1m 7s
System (1.20.x, cluster, btrfs)	1m 32s
Client (1.20.x, windows-latest)	1m 17s
System (1.20.x, cluster, lvm)	1m 26s
System (1.20.x, cluster, zfs)	1m 29s
System (1.20.x, cluster, ceph)	1m 31s
System (1.20.x, cluster, random)	1m 25s
System (1.20.x, standalone, dir)	1m 28s
System (1.20.x, standalone, btrfs)	1m 30s
System (1.20.x, standalone, lvm)	1m 20s
System (1.20.x, standalone, zfs)	1m 28s
System (1.20.x, standalone, ceph)	1m 29s
System (1.20.x, standalone, random)	1m 20s
System (stable, cluster, dir)	1m 14s
System (stable, standalone, dir)	1m 16s
System (tip, cluster, dir)	1m 28s
System (tip, standalone, dir)	1m 29s
	30m 30s

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