stubby: Add multi WAN support for procd trigger

[jamesmacwhite]

Maintainer: No one, previous maintainer no longer wishes to be a maintainer see #15723 (comment)

Compile tested: N/A
Run tested: Linksys WRT3200ACM OpenWrt 19.07.7

Description:

This adds multi WAN trigger support for stubby, in the stubby config you can now supply multiple WAN interfaces separated with a space, currently you cannot do this. For multi WAN environments you would most likely want to have Stubby be able to have triggers on multiple WAN interfaces to not break DNS resolution if a WAN interface goes down.

Original credit/author: https://forum.openwrt.org/t/stubby-option-trigger-help/56694

As this is minor change to the init script, can this also be cherry picked across 21.02 and 19.07?

[dibdot]

Hi, thanks for the contribution. A few remarks:

• This seems to be copied 1:1 from ancient adblock init script in 18.06 branch (see https://github.com/openwrt/packages/blob/openwrt-18.06/net/adblock/files/adblock.init for reference). The cases 'none' or 'timed' are not handled by stubby - therefore please just remove the outer if clause.
• Please bump the PKG_RELEASE in the Makefile as well

Thanks!

[jamesmacwhite]

Hi @dibdot, thanks for your feedback and guidance! I have updated the PR as requested with those changes.

Please me know if this is OK and ready for merging.

[dibdot]

LGTM - many thanks!