🐛 Fix error message when fetching the instance details fails

[rcannood]

Related to:

Description

My JWT token expired, but trying to connect to an instance resulted in the following error:

> devtools::install()
> library(laminr)
> db <- connect("laminlabs/cellxgene")
db$Artifact
Error in `rlang::abort()`:
! `message` must be a character vector, not a list.
Run `rlang::last_trace()` to see where the error occurred.

Checklist

Before review

• Update and regenerate man pages
• Add/update tests
• Add/update examples in vignettes
• Pass CI checks

Before merge

• Update architecture vignette
• Update development vignette
• Update features in README
• Update CHANGELOG