BUG: Only access meta when it exists

[pllim]

Description

This pull request is to address an alleged crash that I cannot reproduce. But from the given traceback, I think this patch would have fixed it but maybe Kyle (the reporter) or Brett (the original code author) can confirm. Since this is to patch an unreleased feature (#2179), there is no need for change log.

Instead of crashing, I see the subset highlighted for the fake WCS layer, which I think is a completely different issue. This screenshot shows the subset overlay on the small fake WCS layer as a rectangle (it was drawn as a circle):

Change log entry

• Is a change log needed? If yes, is it added to CHANGES.rst? If you want to avoid merge conflicts,
  list the proposed change log here for review and add to CHANGES.rst before merge. If no, maintainer
  should add a no-changelog-entry-needed label.

Checklist for package maintainer(s)

This checklist is meant to remind the package maintainer(s) who will review this pull request of some common things to look for. This list is not exhaustive.

• Are two approvals required? Branch protection rule does not check for the second approval. If a second approval is not necessary, please apply the trivial label.
• Do the proposed changes actually accomplish desired goals? Also manually run the affected example notebooks, if necessary.
• Do the proposed changes follow the STScI Style Guides?
• Are tests added/updated as required? If so, do they follow the STScI Style Guides?
• Are docs added/updated as required? If so, do they follow the STScI Style Guides?
• Did the CI pass? If not, are the failures related?
• Is a milestone set? Set this to bugfix milestone if this is a bug fix and needs to be released ASAP; otherwise, set this to the next major release milestone.
• After merge, any internal documentations need updating (e.g., JIRA, Innerspace)? 🐱

[kecnry]

Seems to remove the traceback and I can't think of any obvious unintended consequences. @bmorris3 - does this look reasonable to you?

[bmorris3]

Looks good. 👌🏻

Apologies I missed this earlier.

[pllim]

Thanks for the reviews!