Accents breaks the pdf file name

Hi Florent,

I’m using the last Github version (v1.0003) downloaded today.

When using custom [firstname] and [lastname] tag in the pdf file name, everything works as intended except when the value return an accentued character. I that case the custom tag return empty.

For future release, can you plan to escape the accentued character instead of returning an empty value?

Something like: https://stackoverflow.com/a/10790734

Thanks for your great plugin!