Fix error with describe_distribution() with select

[etiennebacher]

Close #287

library(datawizard)
library(see)

x <- describe_distribution(iris, select = "Sepal.Length")
plot(x)
#> [[1]]
#> `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

x <- describe_distribution(iris, select = starts_with("Sepal"))
plot(x)
#> [[1]]
#> `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

#> 
#> [[2]]
#> `stat_bin()` using `bins = 30`. Pick better value with `binwidth`.

[etiennebacher]

Failing tests on examples and vignettes were already there before