Encointer runtime upgrade to v15 (whitelisted)

Encointer has a new runtime upgrade ready with new features:

Release 1.5.0 for runtime v15: https://github.com/encointer/encointer-parachain/releases/tag/1.5.0

• add faucet functionality
• add reputation commitments for personhood oracle
• this runtime is built on polkadot-v0.9.42
• Changes since v12: https://github.com/encointer/encointer-parachain/compare/1.3.2…1.5.0

proposed call: authorizeUpgrade call on Encointer:

0x0102dfcb7cf28fa3d9af8810d0aec33d2b8e1d5a7164cc7b33d1cab7e7282bd73689

for whitelisting referendum, see: 

https://kusama.polkassembly.io/post/2597