This reverts commit 4aa52d267f000f84caf912c62fc14a5b8e7cacb5.
It turns out that the other implementations set values for this field
which aren't based on the actual capacity of the channel. As a result,
we'll no reject most of their channel offerings, since they may offer a
value of a max `uint64` or something else hard coded that's above the
size of the channel. As a result, we're reverting this check for now to
maintain proper compatibility.
In this commit we add a new command line option (and a sane default) to
allow users to specify the *smallest* inbound channel that they'll
accept. Having a higher-ish limit lets users limit their channels, and
also avoid a series of very low value "spam" channels.
The new option is --minchansize, and expressed in satoshis. If we
receive an inbound channel request for a value smaller than this, then
we'll immediately reject it.