lnchannel: save timestamp when we settle
lnchannel: save timestamp when we settle

wakiyamap/electrum-mona,spesmilo/electrum,pooler/electrum-ltc,pooler/electrum-ltc,wakiyamap/electrum-mona,vialectrum/vialectrum,pooler/electrum-ltc,vialectrum/vialectrum,pooler/electrum-ltc,spesmilo/electrum,spesmilo/electrum,spesmilo/electrum,wakiyamap/electrum-mona,wakiyamap/electrum-mona,vialectrum/vialectrum