procd: Fix sysupgrade services stop

Openwrt with procd commit: https://git.openwrt.org/?p=project/procd.git;a=commitdiff;h=87b583635475c56ae5b8ec89233f6f292ba09765 introduced stopping all services during sysupgrade. With our sysupgrade approach we don't need to stop any services.

Decided to not revert whole commit introducing services stopping too keep our changes small.

refs #8350