lnwallet/channel: remove restoreHtlc from pendingRemoteCommit
lnwallet/channel: remove restoreHtlc from pendingRemoteCommit

This commit removes the stage during updateLog restoration where we
would attempt to restore incoming HLTCs from the pendingRemoteCommit, in
addition to update our log and htlc counter to reflect this state. The
reason we can safely remove this is to observe that a pending remote
commit is always created from a commitDiff which only contains updates
made by _us_, and thus only taken from the localUpdateLog. The same can
be said for the counters, when creating a commitDiff we'll always use
the remoteACKedIndex as the index into the remoteUpdateLog, meaning that
all potential updates will already be included in the remote commit that
has been ACKed.

LightningNetwork/lnd,aakselrod/lnd,aakselrod/lnd,LightningNetwork/lnd