Fixes broken language cookie

Header before:
`Set-Cookie: django_language=en-us; expires=time.struct_time(tm_year=2014, tm_mon=5, tm_mday=29, tm_hour=6, tm_min=56, tm_sec=54, tm_wday=3, tm_yday=149, tm_isdst=0); Max-Age=31536000; Path=/`

In addition to a language cookie, this would set cookies for each item in the struct_time tuple: tm_year, tm_mon, etc.

Header after:
`Set-Cookie: django_language=en-us; expires=Thu, 29-May-2014 14:40:53 GMT; Max-Age=31536000; Path=/`

I think this is what was intended in the first place and it sets only the language cookie.

Signed-off-by: Martin Koistinen <mkoistinen@gmail.com>