cfg: move experimental options to main protocol cfg

lncfg/protocol_experimental_off.go

@@ -3,23 +3,7 @@
 
 package lncfg
 
-import (
-	"github.com/lightningnetwork/lnd/feature"
-	"github.com/lightningnetwork/lnd/lnwire"
-)
-
 // ExperimentalProtocol is a sub-config that houses any experimental protocol
 // features that also require a build-tag to activate.
 type ExperimentalProtocol struct {
 }
-
-// CustomMessageOverrides returns the set of protocol messages that we override
-// to allow custom handling.
-func (p ExperimentalProtocol) CustomMessageOverrides() []uint16 {
-	return nil
-}
-
-// CustomFeatures returns a custom set of feature bits to advertise.
-func (p ExperimentalProtocol) CustomFeatures() map[feature.Set][]lnwire.FeatureBit {
-	return map[feature.Set][]lnwire.FeatureBit{}
-}