Fixed edge case where n_versions = 0

[MichalLauer]

Fixes #837.

Here is a reprex of the fix:

library(pins)

# Prepare data
write.csv(mtcars, file = "mtcars.csv")

# Create temp board and first upload
board <- board_temp(versioned = TRUE)
pin_upload(board = board, paths = "mtcars.csv", name = "data")
#> Creating new version '20240827T112516Z-cd94d'

# Returns one version
pin_versions(board, "data")
#> # A tibble: 1 × 3
#>   version                created             hash 
#>   <chr>                  <dttm>              <chr>
#> 1 20240827T112516Z-cd94d 2024-08-27 13:25:16 cd94d

# Delete just created pin
latest_version <- pin_versions(board = board, name = "data")$version
pin_version_delete(board = board, name = "data", version = latest_version)

# Returns an empty tibble
pin_versions(board, "data")
#> # A tibble: 0 × 3
#> # ℹ 3 variables: version <chr>, created <dttm>, hash <chr>

# Upload new data
pin_upload(board = board, paths = "mtcars.csv", name = "data")
#> Creating new version '20240827T112516Z-cd94d'

# Returns one version
pin_versions(board, "data")
#> # A tibble: 1 × 3
#>   version                created             hash 
#>   <chr>                  <dttm>              <chr>
#> 1 20240827T112516Z-cd94d 2024-08-27 13:25:16 cd94d

^{Created on 2024-08-27 with reprex v2.1.1}

I also simplified the if statement in version_setup as the solution introduced another layer of if-else statements.
If anything is missing, feel free to let me know :)

[juliasilge]

Thanks so much @MichalLauer! 🙌

[MichalLauer]

Thank you too @juliasilge! 🥇

[github-actions]

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