lint_package fails if .lintr does not end with new line

[dirkschumacher]

Just observed the following error. If it is a feature and not a bug, then it might make sense to improve the error message. Tested on a Mac.

cat("linters: with_defaults(closed_curly_linter = NULL)", file = ".lintr")
lintr::lint_package()

=> Error in mapply(function(from, to) paste(lines[from:to], collapse = "\n")

cat("linters: with_defaults(closed_curly_linter = NULL)\n", file = ".lintr")
lintr::lint_package()

This works as intented.