validate_email() documentation mis-specifies config location

[ms609]

The documentation of validate_email() in R/email.R@9,10 contains the text

#' On your current platform the file is at
#' \Sexpr{rhub:::email_file()}`

The Sexpr is executed when the package is compiled – so when downloading the binary package from CRAN, it reads

On your current platform the file is at C:\Users\CRAN\AppData\Local/rhub/rhub/validated_emails.csv.

I'm not sure what the most appropriate fix is: perhaps we need a wrapper for email_file() that detects that the package is being built on CRAN, and perhaps replaces the string C:\Users\CRAN\AppData\Local with %APPDATA%?