improve help text regarding watchtower
improve help text regarding watchtower

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