lnbase: use sign_next_commitment for initial remote_ctx
lnbase: use sign_next_commitment for initial remote_ctx

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