[security update] www/py-django : update to 2.1.3 and 1.11.16

[wen heping]

Hi,

    The patch update www/py-django lts to 1.11.16 and stable to 2.1.3.
    The update of stable include a security fix(CVE-2018-16984).
    It build well on my amd64 system.

    Comments? OK ?

wen