Fix creation of IBSS interfaces on devices with two radios

Lua's tables are 1-based, so we must decrement the index by 1 to get the
desired MAC addresses. By not doing this, the second IBSS interface would
get the address with index 8, but only indices 0..7 are available.

Fixes: c73a12e0ea9fd6bb48927f0a03367354b5897ddc

package/gluon-client-bridge/files/lib/gluon/upgrade/320-gluon-client-bridge-wireless

@@ -21,7 +21,7 @@ local function configure_client(config, radio, index, suffix)
 
   uci:delete('wireless', name)
 
-  macaddr = util.generate_mac(3*index)
+  macaddr = util.generate_mac(3*(index-1))
 
   if config and macaddr then
     uci:section('wireless', 'wifi-iface', name,

package/gluon-mesh-batman-adv-core/files/lib/gluon/upgrade/320-gluon-mesh-batman-adv-core-wireless

@@ -29,7 +29,7 @@ local function configure_ibss(config, radio, index, suffix, disabled)
   uci:delete('network', name .. '_vlan')
   uci:delete('wireless', name)
 
-  macaddr = util.generate_mac(3*index+2)
+  macaddr = util.generate_mac(3*(index-1)+2)
 
   if config and macaddr then
     if config.vlan then
@@ -79,7 +79,7 @@ local function configure_mesh(config, radio, index, suffix, disabled)
   uci:delete('network', name)
   uci:delete('wireless', name)
 
-  macaddr = util.generate_mac(3*index+1)
+  macaddr = util.generate_mac(3*(index-1)+1)
 
   if config and macaddr then
     uci:section('network', 'interface', name,