FS#3965 - MAC addresses should be kept as in 19.07

[openwrt-bot]

regulskimichal:

Supply the following if possible:

• Device problem occurs on: WRT1200AC
• Software versions of OpenWrt/LEDE release, packages, etc.: 21.02
• Steps to reproduce: Clean install

After upgrading from 19.07 to 21.02 I found out issues with IP addresses given by my ISP. I found out that the MAC address of the WAN port has changed instead of LAN (before LAN started with 26 and WAN 24 but after upgrading it was the opposite - LAN started with 24 and WAN with 26). It is a very confusing behavior and addressing and IMO it should stay as it was in previous versions.