treewide: move sysctl settings to /etc/sysctl.d

net.ipv6.conf.br-client.forwarding is moved from gluon-client-bridge to
gluon-mesh-batman-adv, as the setting is not useful with non-bridged
protocols.

package/gluon-client-bridge/luasrc/lib/gluon/upgrade/300-gluon-client-bridge-network

 #!/usr/bin/lua
 
 local sysconfig = require 'gluon.sysconfig'
-local sysctl = require 'gluon.sysctl'
 local util = require 'gluon.util'
 
 local uci = require('simple-uci').cursor()
@@ -72,6 +71,3 @@ uci:section('dhcp', 'dhcp', 'local_client', {
 
 uci:save('dhcp')
 uci:save('firewall')
-
-
-sysctl.set('net.ipv6.conf.br-client.forwarding', 0)

package/gluon-core/files/etc/sysctl.d/30-gluon-core.conf

+vm.panic_on_oom=1

package/gluon-core/luasrc/lib/gluon/upgrade/110-network

 #!/usr/bin/lua
 
 local uci = require('simple-uci').cursor()
-local sysctl = require 'gluon.sysctl'
 local sysconfig = require 'gluon.sysconfig'
 
 
@@ -68,7 +67,3 @@ uci:section('firewall', 'rule', 'wan_mld', {
 })
 
 uci:save('firewall')
-
-
-sysctl.set('net.ipv6.conf.all.accept_ra', 0)
-sysctl.set('net.ipv6.conf.default.accept_ra', 0)

package/gluon-core/luasrc/lib/gluon/upgrade/130-reboot-on-oom

-#!/usr/bin/lua
-
-local sysctl = require 'gluon.sysctl'
-
-sysctl.set('vm.panic_on_oom', 1)

package/gluon-mesh-batman-adv/files/etc/sysctl.d/31-gluon-mesh-batman-adv.conf

+net.ipv6.conf.br-client.forwarding=0
+net.ipv6.conf.local-node.forwarding=0

package/gluon-mesh-batman-adv/luasrc/lib/gluon/upgrade/320-gluon-mesh-batman-adv-client-bridge

@@ -6,7 +6,6 @@
 
 local site = require 'gluon.site'
 local sysconfig = require 'gluon.sysconfig'
-local sysctl = require 'gluon.sysctl'
 local util = require 'gluon.util'
 local uci = require('simple-uci').cursor()
 
@@ -51,6 +50,3 @@ uci:set_list('firewall', 'drop', 'network', networks)
 uci:delete('firewall', 'local_node_dns')
 
 uci:save('firewall')
-
-
-sysctl.set('net.ipv6.conf.local-node.forwarding', 0)