liburiparser: bump to version 0.8.6

Version 0.8.6 is a bugfix release including a nasty bug that has
potential to crash applications when parsing certain URIs (like
"//:%aa@", excluding quotes).

For more details please check the change log at

    https://github.com/uriparser/uriparser/blob/uriparser-0.8.6/ChangeLog



Signed-off-by: Carlos Santos <casantos@datacom.com.br>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>