Feature request: max amount option when choosing new channel amount

[Eylrid]

I put a few millibits into the wallet intending to put it all (less fees) into a channel, but there is no easy way to put the max amount into a channel.

Something like your "Empty wallet" option when sending an on chain transaction is what I'm looking for, but for opening a channel.

[irekzielinski]

+1
it's a frequent use case:

• send some coins to eclair
• put all of those into LN channel

right now it's almost impossible to avoid dust output,
having a MAX option that spends all funds - miner fee (and creates a single output) would be very desirable. LBW has such option and it works great.

[githorray]

The "Use all available funds" option adds one sat too many, resulting in the error "Channel capacity must be between 100,000 and 16,777,216 sat"