ChannelDB.on_node_announcement: some speed-up
ChannelDB.on_node_announcement: some speed-up

(e.g. for 100 node anns, was ~5 seconds, now 0.7 sec; so still slow)

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