channeldb: remove unused fwdPackageLogBucket key

In this commit, we move the declaration of the key for an unused bucket.
In the past, this bucket was used to store the revocation forwarding
package log. However, this has been moved under the key
`fwdPackagesKey`.

channeldb/channel.go

@@ -70,12 +70,6 @@ var (
 	// channel closure. This key should be accessed from within the
 	// sub-bucket of a target channel, identified by its channel point.
 	revocationLogBucket = []byte("revocation-log-key")
-
-	// fwdPackageLogBucket is a bucket that stores the locked-in htlcs after
-	// having received a revocation from the remote party. The keys in this
-	// bucket represent the remote height at which these htlcs were
-	// accepted.
-	fwdPackageLogBucket = []byte("fwd-package-log-key")
 )
 
 var (