byobu cannot connect to session if $HOME is read-only

[Stdedos]

If there is a session to connect to
```
[3] root@mgmt ~ # ps faxu | grep tmux
root 12855 0.0 0.0 15444 964 pts/3 S+ 11:52 0:00 \_ grep --colour=auto tmux
root 22608 0.8 0.5 69128 44064 ? Ss Mar01 486:29 tmux -u -2 -f /usr/local/share/byobu/profiles/tmuxrc new-session -n - /usr/local/bin/byobu-shell
```

I expect that I should be able to connect regardless
```
[3] root@mgmt ~ # byobu
rm: cannot remove '/root/.byobu/.metadata_available': Read-only file system
```

```
[3] root@mgmt ~ # byobu --version
byobu version 5.133
tmux 3.1b
```