Describe the bug
multipass aliases command throws segmentation fault after launching the docker blueprint, if and only if there are no other aliases defined.

To Reproduce
Given there are no aliases defined and multipass aliases should yield No aliases defined.

1. launch an instance of the docker blueprint with multipass launch docker
2. execute multipass aliases, segmentation fault happens here
3. create an alias with multipass alias docker:hello
4. execute multipass aliases, back to normal, no errors here

Expected behavior
multipass aliases should return list of aliases without error

Additional info

• OS: macOS 14.2.1
• multipass version
  • multipass 1.13.0+mac
  • multipassd 1.13.0+mac
• multipass info --all
  • Name: docker
    State: Running
    Snapshots: 0
    IPv4: 192.168.101.24
    172.17.0.1
    Release: Ubuntu 22.04.3 LTS
    Image hash: f885a8e8f62a (Ubuntu 22.04 LTS)
    CPU(s): 2
    Load: 0.97 0.46 0.17
    Disk usage: 2.5GiB out of 38.7GiB
    Memory usage: 254.7MiB out of 3.8GiB
    Mounts: /Users/minh/multipass/docker => docker
    UID map: 501:default
    GID map: 20:default
• multipass get local.driver
  • qemu