[tlbuild] Minor fix for poppler

[Mojca Miklavec]

On 15 January 2018 at 23:59, Karl Berry wrote:
>     The following patch is needed for poppler in order to make time_t work
>     on FreeBSD 11.1:
>
>     --- libs/poppler/poppler-src/poppler/Form.h (revision 46316)
>     +++ libs/poppler/poppler-src/poppler/Form.h (working copy)
>     ...
>     +#include <ctime>
>
> Committed, thanks. Please tell upstream if you haven't already. -k

https://bugs.freedesktop.org/show_bug.cgi?id=104674

Mojca