config+protocol: enable anchor commitments (zero-fee HTLC ) by default

lncfg/protocol_experimental_off.go

@@ -6,9 +6,3 @@ package lncfg
 // features that also require a build-tag to activate.
 type ExperimentalProtocol struct {
 }
-
-// AnchorCommitments returns true if support for the anchor commitment type
-// should be signaled.
-func (l *ExperimentalProtocol) AnchorCommitments() bool {
-	return false
-}