miniupnpd: lease bump to 2.3.6

[brada4]

Maintainer: none @stangri @stintel @jow-

Environment: x86_64 aarch64 ramips 23.05.0-3 snapshot

Description:

Present v2.3.3 has 2 defects in natpmp handling.
It creates wrong forward/accept rules in 2 ways:
if natpmp protocol is udp it creates tcp accept rule
if natpmp destination port != source port it creates rule regarding post-nat destination port
Both ways traversal does not happen at all.

Somewhat misguided maybe, but bypass attempt openwrt/firewall4#28
Tried myself, https mirror still not avail https://forum.openwrt.org/t/how-to-proceed-updating-miniupnpd-233-236/194183
It works perfectly.