extending OpenWrt packages maintainers by a new member

[Luka Perkov]

Dear all,

i would like to propose granting Marko Ratkaj (ratkaj on GitHub) commit access.

Over the last few years that I know him personally, Marko has done a
lot of great work. He maintains a dozen of packages and is actively
porting new ones to OpenWrt. He is very knowledgeable about
OpenWrt/LEDE in general and he actively pushes new packages and fixes
issues in existing ones within the packages feed.

That being said, he has my vote to gain access to the above mentioned feed.

Thanks,
Luka