i3xrocks seg fault if Xresource regolith.look.path invalid

[pjz]

• [x] I've run a search on the existing bug reports to make sure I'm not filing a duplicate (you can use the search box at the top left corner)
• [x] I've read the Regolith documentation and didn't find any relevant topic
• [x] I tried asking on Slack (especially for configuration related issues)

Describe the bug i3xrocks seg faults if the file pointed to by Xresource regolith.look.path doesn't exist

To Reproduce

• change your look to something like, say, i3-default.
• uninstall the regolith-look-i3-default package.
• restart i3

Expected behavior I'd expect a warning message in the bar about 'unrecognized look' or something, or maybe a popup message saying "hey, regolith.look.path is invalid'. NOT a gripe that status_command is failing (which it is, because it segfaults)

Installation Details

• Regolith Install Type: [PPA]
• Regolith Version: [4.2.0-1regolith]
• PPA url: [https://regolith-desktop.org/release-ubuntu-jammy-amd64e]
• Host OS (for PPA): [Ubuntu 22.04]