Allow Nomination pool configuration changes with StakingAdmin.

[Ank4n]

set_config should be set by StakingAdmin instead of root.

[iMac7]

Hi @Ank4n
I'm a newcomer to this repo, not as new to the polkadot ecosystem. I like to pick up issues to give me a starting point to look around, this one looks promising :)

Just a few noob questions (to you or assigned mentor).
Is this done in /substrate (pallet issue) or /polkadot or other folder?
Where can I find the nomination pool config?
How would I test this locally? Assume I have cloned the repo and installed all dependencies. Nothing more satisfying than making changes to a local tiny blockchain 😄

[Ank4n]

Hey @iMac7 thanks for your interest. Sorry I have already worked on it so this is unfortunately not up for mentor. But I hope you find another good first issue.