This adds a script to init.d to automatically call
the appropriate configure-layer3 commands after an upgrade,
so the configuration of the device is restored.
The changes are applied if configure-layer3 is successful.
Otherwise, they are reverted. Due to this, no additional checks for
the configuration are necessary: The configure-layer3 script
will fail if the config version is wrong or no configuration exists at all.
After executing the script destroys itself. With START=99,
the execution happens _after_ uci-defaults and configurenetwork,
and no interference is expected.
Signed-off-by: Fabian Bläse <fabian@blaese.de>
[convert to init.d, extend commit message, rebase]
Signed-off-by: Christian Dresel <freifunk@dresel.systems>